Take management: move takes onto the clip instance

Take management should be per clip instance — deleting a take from one
half of a comped split shouldn't pull it out from under the other half.
That's cleanest if the takes themselves live on the instance rather than
the clip, so they do now.

AudioClipType::TakeFolder is gone entirely. A clip is plain Sampled/Midi
content again, and an instance with a non-empty `takes` list simply
OVERRIDES it with whichever take is active. Splitting already clones the
instance, so each half gets its own take list for free — no index
remapping across instances, no copy-on-write, no shared-state surprise —
and comping still works, because the halves can still each select a
different take. It collapsed machinery too: resolve() moved from the clip
to the instance, and owns_audio_pool_index went back to a one-liner.

Management (DeleteTakeAction, DeleteUnusedTakesAction, RenameTakeAction):
- Right-click a clip with more than one take: `Delete "<active take>"`
  and "Delete Unused Takes". Deletion is named after the take that's
  PLAYING rather than being a generic entry, so you pick the victim by
  selecting it — one clear act instead of hunting a small trash icon in a
  list (which is where this started, and it was fiddly).
- Double-click a take in the dropdown to rename it in place.
- What happens to the selection on delete is the subtle part, and there's
  a test per case: deleting a take BELOW the active one shifts the
  selection down so you keep hearing the same take; deleting the ACTIVE
  take lands on whatever slid into its place (not silently back to take
  1); deleting the LAST take steps back one. The only take can't be
  deleted at all — the menu item isn't offered.
- Deleted takes' audio stays in the pool: undo has to put it back, and
  the other half of a split may still be playing it.

Fixes:
- A recording that stopped before the loop came round wasn't joining an
  existing take list — it landed as a separate overlapping clip. Trigger-
  on-wrap is right for the FIRST recording, but once takes exist there,
  a further run is plainly another take however short. The engine can't
  know that (it's document state), so the editor passes `force_takes`
  with the start-recording command and the run is cut and padded to the
  region even with zero wraps. This forced cycle_loop_len and `wrapped`
  apart on the MIDI side: the region length has to be known from the
  start, but the clip should only pin to full-region length AFTER a pass
  completes, or the bar jumps to full width the moment you hit record.
- Recording a second take left BOTH sounding. append_cycle_takes tore
  down the recording's backend clip by looking it up in
  clip_instance_to_backend_map — but on the audio path the recording
  instance isn't in that map yet; it's only added during promotion, which
  the append path skips. The event already carries the engine's clip id,
  so it's handed over explicitly now.
- The take badge is hidden when there's only one take — no choice to make.

daw-backend/src/audio/export.rs

@@ -211,6 +211,7 @@ pub fn render_to_memory(
             settings.sample_rate,
             settings.channels,
             false,
+            None, // export never runs with a recording in flight
         );
 
         // Calculate how many samples we actually need from this chunk
@@ -557,6 +558,7 @@ fn export_mp3<P: AsRef<Path>>(
             settings.sample_rate,
             settings.channels,
             false,
+            None, // export never runs with a recording in flight
         );
 
         // Calculate how many samples we need from this chunk
@@ -727,6 +729,7 @@ fn export_aac<P: AsRef<Path>>(
             settings.sample_rate,
             settings.channels,
             false,
+            None, // export never runs with a recording in flight
         );
 
         // Calculate how many samples we need from this chunk

daw-backend/src/audio/project.rs

@@ -383,6 +383,7 @@ impl Project {
         sample_rate: u32,
         channels: u32,
         live_only: bool,
+        recording_midi: Option<(TrackId, MidiClipId)>,
     ) {
         output.fill(0.0);
 
@@ -391,6 +392,7 @@ impl Project {
         // Create initial render context
         let ctx = RenderContext {
             live_only,
+            recording_midi,
             ..RenderContext::new(playhead_seconds, tempo_map, sample_rate, channels, output.len())
         };
 

daw-backend/src/audio/recording.rs

@@ -5,6 +5,61 @@ use crate::time::{Beats, Seconds};
 use std::collections::HashMap;
 use std::path::PathBuf;
 
+/// Cycle-recording bookkeeping attached to a recording that started with a cycle region armed.
+///
+/// Takes are sliced **geometrically** at stop, in exact `loop_len_frames` multiples — not at the
+/// instant the wrap was detected. The playhead advances before the capture block in `process()`, so
+/// the wrap instant isn't sample-exact against the buffer that was just captured, but the geometry
+/// is. `wrap_count` therefore only decides *whether* this is a multi-take recording, never where the
+/// cuts land.
+#[derive(Debug, Clone, Copy)]
+pub struct CycleRecordInfo {
+    /// Where the cycle region starts, in beats. Takes are laid down here, not at the punch-in point.
+    pub loop_start: Beats,
+    /// The cycle region's length in beats — what the take folder records as `recorded_loop_beats`.
+    pub loop_len_beats: Beats,
+    /// One cycle pass, in frames. The take size.
+    pub loop_len_frames: usize,
+    /// Frames between the region start and where capture actually began. Non-zero only for a
+    /// punch-in (record while already rolling); take 1 gets this much silence prepended so it still
+    /// spans the whole region.
+    pub lead_pad_frames: usize,
+    /// How many times the transport wrapped during this recording. Zero normally means the user
+    /// stopped before completing a pass, which stays an ordinary single recording — unless
+    /// `force_takes` says otherwise.
+    pub wrap_count: usize,
+    /// Cut takes even if the transport never wrapped.
+    ///
+    /// Set when the region already holds takes: a further recording there is another take, however
+    /// short, and it gets padded out to the region like any partial pass. Without this a run that
+    /// stopped before the loop came round would land as a separate overlapping clip instead of
+    /// joining the take list.
+    ///
+    /// The editor decides this at record start, because whether takes already exist is document
+    /// state the engine can't see.
+    pub force_takes: bool,
+}
+
+/// Min/max waveform peaks for a finished buffer of interleaved samples.
+///
+/// The live recording path builds its peaks incrementally as samples arrive; cycle takes don't
+/// exist until the recording is sliced at stop, so they get theirs in one pass here.
+pub fn compute_peaks(samples: &[f32], channels: u32, frames_per_peak: usize) -> Vec<WaveformPeak> {
+    let samples_per_peak = (frames_per_peak * channels.max(1) as usize).max(1);
+    samples
+        .chunks(samples_per_peak)
+        .map(|chunk| {
+            let mut min = 0.0f32;
+            let mut max = 0.0f32;
+            for s in chunk {
+                min = min.min(*s);
+                max = max.max(*s);
+            }
+            WaveformPeak { min, max }
+        })
+        .collect()
+}
+
 /// State of an active recording session
 pub struct RecordingState {
     /// Track being recorded to
@@ -35,6 +90,8 @@ pub struct RecordingState {
     pub frames_per_peak: usize,
     /// All recorded audio data accumulated in memory (written to disk at finalization)
     pub audio_data: Vec<f32>,
+    /// Cycle-recording bookkeeping, when a cycle region was armed at record start.
+    pub cycle: Option<CycleRecordInfo>,
 }
 
 impl RecordingState {
@@ -69,9 +126,69 @@ impl RecordingState {
             waveform_buffer: Vec::new(),
             frames_per_peak,
             audio_data: Vec::new(),
+            cycle: None,
         }
     }
 
+    /// Slice the recording into cycle takes: one per pass, each spanning the FULL cycle region.
+    ///
+    /// Partial passes are padded with silence — the head of take 1 for a punch-in, the tail of the
+    /// last take when the user stops mid-pass — so every take is the same length and aligned to the
+    /// region. That uniformity is what makes comping-via-split work: take 1 on the left half and
+    /// take 3 on the right always line up.
+    ///
+    /// Returns `None` if this wasn't a cycle recording or the transport never wrapped (an ordinary
+    /// single recording, which keeps the existing path untouched).
+    pub fn slice_takes(&self) -> Option<Vec<Vec<f32>>> {
+        let cycle = self.cycle?;
+        if (cycle.wrap_count == 0 && !cycle.force_takes) || cycle.loop_len_frames == 0 {
+            return None;
+        }
+
+        let ch = self.channels.max(1) as usize;
+        let take_len = cycle.loop_len_frames * ch;
+        let lead = cycle.lead_pad_frames * ch;
+
+        // The recording as positioned *within the region*: silence for the gap between the region
+        // start and the punch-in, then the captured audio. Slicing this at whole-take boundaries is
+        // the whole trick — take 1 comes out short-by-`lead` at the front, already padded.
+        let virtual_len = lead + self.audio_data.len();
+        let take_count = virtual_len.div_ceil(take_len);
+
+        let mut takes: Vec<Vec<f32>> = Vec::with_capacity(take_count);
+        for i in 0..take_count {
+            let mut take = vec![0.0f32; take_len];
+            let take_begin = i * take_len;
+            for slot in 0..take_len {
+                // Position in the virtual (lead-padded) buffer.
+                let v = take_begin + slot;
+                if v < lead {
+                    continue; // still in the punch-in silence
+                }
+                match self.audio_data.get(v - lead) {
+                    Some(s) => take[slot] = *s,
+                    None => break, // past the end of capture; the rest stays silent
+                }
+            }
+            takes.push(take);
+        }
+
+        // A final take holding only a sliver of real audio is a stop artifact (the user hit stop a
+        // moment after the wrap), not a performance. Drop it — but only if it's actually a PARTIAL
+        // pass, and never the only take. A pass that filled the region is a real take no matter how
+        // short the region is.
+        const MIN_TAKE_SECONDS: f64 = 0.05;
+        if takes.len() > 1 {
+            let last_real_samples = virtual_len - (takes.len() - 1) * take_len;
+            let last_real_seconds = (last_real_samples / ch) as f64 / self.sample_rate as f64;
+            if last_real_samples < take_len && last_real_seconds < MIN_TAKE_SECONDS {
+                takes.pop();
+            }
+        }
+
+        Some(takes)
+    }
+
     /// Add samples to the accumulation buffer
     /// Returns true if a flush occurred
     pub fn add_samples(&mut self, samples: &[f32]) -> Result<bool, std::io::Error> {
@@ -189,6 +306,26 @@ pub struct MidiRecordingState {
     active_notes: HashMap<u8, ActiveMidiNote>,
     /// Completed notes: (time_offset, note, velocity, duration) — all times in beats
     pub completed_notes: Vec<(Beats, u8, u8, Beats)>,
+    /// The cycle region's length in beats, if one was armed at record start.
+    ///
+    /// A cycle MIDI recording is anchored at the region start (`start_time == loop_start`), which is
+    /// what makes MERGE fall out for free: the transport always wraps back into the region, so every
+    /// note's offset already lands inside `[0, loop_len)` and successive passes overdub onto each
+    /// other with no folding needed.
+    pub cycle_loop_len: Option<Beats>,
+    /// Whether the transport actually came round. Distinct from `cycle_loop_len`, which only says a
+    /// region was armed: the clip only pins to the full region once a pass has completed, so until
+    /// then the bar still grows with the playhead.
+    pub wrapped: bool,
+    /// Cut takes even if the transport never wrapped — see [`CycleRecordInfo::force_takes`].
+    pub force_takes: bool,
+    /// Which cycle pass is currently being recorded (0-based). Bumped at each wrap.
+    current_pass: usize,
+    /// The pass each completed note belongs to, parallel to `completed_notes`.
+    ///
+    /// Only meaningful in "separate takes" mode, where each pass becomes its own MIDI clip. Merge
+    /// mode ignores it — all passes fold into one clip, which is the whole point.
+    note_pass: Vec<usize>,
 }
 
 impl MidiRecordingState {
@@ -199,9 +336,28 @@ impl MidiRecordingState {
             start_time,
             active_notes: HashMap::new(),
             completed_notes: Vec::new(),
+            cycle_loop_len: None,
+            wrapped: false,
+            force_takes: false,
+            current_pass: 0,
+            note_pass: Vec::new(),
         }
     }
 
+    /// Record a finished note, tagging it with the pass it was played in.
+    ///
+    /// Every completion goes through here so `completed_notes` and `note_pass` can't drift apart.
+    fn push_completed(&mut self, note: &ActiveMidiNote, end_time: Beats) {
+        let note_start = note.start_time.max(self.start_time);
+        self.completed_notes.push((
+            note_start - self.start_time,
+            note.note,
+            note.velocity,
+            end_time - note_start,
+        ));
+        self.note_pass.push(self.current_pass);
+    }
+
     pub fn note_on(&mut self, note: u8, velocity: u8, absolute_time: Beats) {
         self.active_notes.insert(note, ActiveMidiNote { note, velocity, start_time: absolute_time });
     }
@@ -211,16 +367,38 @@ impl MidiRecordingState {
             if absolute_time <= self.start_time {
                 return;
             }
-            let note_start = active_note.start_time.max(self.start_time);
+            self.push_completed(&active_note, absolute_time);
-            self.completed_notes.push((
-                note_start - self.start_time,
-                active_note.note,
-                active_note.velocity,
-                absolute_time - note_start,
-            ));
         }
     }
 
+    /// Completed notes grouped by cycle pass — one bucket per pass, in recording order.
+    ///
+    /// Used by "separate takes" mode, where each pass becomes its own MIDI clip.
+    ///
+    /// An *interior* pass in which nothing was played still yields an empty take, so take N in the
+    /// folder is always pass N on the transport — otherwise the numbering would silently shift and
+    /// "take 3" would stop meaning "the third time round". A *trailing* empty pass is dropped
+    /// though: that's what you get by hitting stop shortly after a wrap, and it's a stop artifact
+    /// rather than a take you played. (Same reasoning as the audio path's short-final-take rule.)
+    pub fn notes_by_pass(&self, passes: usize) -> Vec<Vec<(Beats, u8, u8, Beats)>> {
+        let mut buckets = vec![Vec::new(); passes.max(1)];
+        for (note, &pass) in self.completed_notes.iter().zip(self.note_pass.iter()) {
+            if let Some(bucket) = buckets.get_mut(pass) {
+                bucket.push(*note);
+            }
+        }
+        // Never drop the only take.
+        while buckets.len() > 1 && buckets.last().is_some_and(|b| b.is_empty()) {
+            buckets.pop();
+        }
+        buckets
+    }
+
+    /// How many cycle passes this recording covered (1 if the transport never wrapped).
+    pub fn pass_count(&self) -> usize {
+        self.current_pass + 1
+    }
+
     pub fn get_notes(&self) -> &[(Beats, u8, u8, Beats)] {
         &self.completed_notes
     }
@@ -229,18 +407,28 @@ impl MidiRecordingState {
         self.completed_notes.len()
     }
 
+    /// The still-held notes, given a provisional duration running to `current_time`.
+    ///
+    /// These belong to whatever pass is in progress, so a per-pass view can append them as-is.
+    pub fn active_notes_with_provisional_end(&self, current_time: Beats) -> Vec<(Beats, u8, u8, Beats)> {
+        self.active_notes
+            .values()
+            .map(|active| {
+                let note_start = active.start_time.max(self.start_time);
+                (
+                    note_start - self.start_time,
+                    active.note,
+                    active.velocity,
+                    (current_time - note_start).max(Beats::ZERO),
+                )
+            })
+            .collect()
+    }
+
     /// Get all completed notes plus currently-held notes with a provisional duration.
     pub fn get_notes_with_active(&self, current_time: Beats) -> Vec<(Beats, u8, u8, Beats)> {
         let mut notes = self.completed_notes.clone();
-        for active in self.active_notes.values() {
+        notes.extend(self.active_notes_with_provisional_end(current_time));
-            let note_start = active.start_time.max(self.start_time);
-            notes.push((
-                note_start - self.start_time,
-                active.note,
-                active.velocity,
-                (current_time - note_start).max(Beats::ZERO),
-            ));
-        }
         notes
     }
 
@@ -252,13 +440,259 @@ impl MidiRecordingState {
         let active_notes: Vec<_> = self.active_notes.drain().collect();
 
         for (_note_num, active_note) in active_notes {
-            let note_start = active_note.start_time.max(self.start_time);
+            self.push_completed(&active_note, end_time);
-            self.completed_notes.push((
-                note_start - self.start_time,
-                active_note.note,
-                active_note.velocity,
-                end_time - note_start,
-            ));
         }
     }
+
+    /// Handle a transport cycle wrap during MIDI recording.
+    ///
+    /// Note times are stored as offsets from `start_time`, and the playhead jumps *backwards* at a
+    /// wrap — so a note still held across the boundary would otherwise get a nonsensical (negative)
+    /// duration, or never be closed at all. Write its note-off at `region_end` (exactly as
+    /// `close_active_notes` does when recording stops), then re-open it at `region_start` so a key
+    /// the player is still physically holding keeps being captured in the next pass. Mirrors the
+    /// way `handle_start_midi_recording` re-injects already-held notes at the recording start.
+    pub fn wrap_at_cycle(&mut self, region_end: Beats, region_start: Beats) {
+        // Snapshot the held notes (close_active_notes drains them and loses the velocities).
+        let held: Vec<(u8, u8)> = self
+            .active_notes
+            .values()
+            .map(|n| (n.note, n.velocity))
+            .collect();
+
+        // Close first, so a note held across the boundary has its tail attributed to the pass that's
+        // ending; then advance, so the re-opened half belongs to the pass that's beginning.
+        self.close_active_notes(region_end);
+        self.current_pass += 1;
+
+        for (note, velocity) in held {
+            self.note_on(note, velocity, region_start);
+        }
+
+        // A pass has completed, so from here the clip spans the whole region rather than however long
+        // the user happens to hold the record button.
+        self.cycle_loop_len = Some(region_end - region_start);
+        self.wrapped = true;
+    }
+}
+
+#[cfg(test)]
+mod cycle_tests {
+    use super::*;
+
+    /// A recording state holding `audio_data`, armed for cycle recording. Mono, 100 Hz, so a frame
+    /// is a sample and 5 frames is 50 ms (exactly the min-take threshold).
+    fn rec_forced(audio: Vec<f32>, loop_len_frames: usize, lead_pad_frames: usize, wraps: usize) -> RecordingState {
+        let mut r = rec(audio, loop_len_frames, lead_pad_frames, wraps);
+        if let Some(c) = r.cycle.as_mut() {
+            c.force_takes = true;
+        }
+        r
+    }
+
+    fn rec(audio: Vec<f32>, loop_len_frames: usize, lead_pad_frames: usize, wraps: usize) -> RecordingState {
+        let mut r = RecordingState::new(
+            0,
+            0,
+            PathBuf::from("/dev/null"),
+            WavWriter::create(&PathBuf::from("/dev/null"), 100, 1).expect("wav writer"),
+            100,
+            1,
+            Beats(0.0),
+            1.0,
+        );
+        r.audio_data = audio;
+        r.cycle = Some(CycleRecordInfo {
+            loop_start: Beats(0.0),
+            loop_len_beats: Beats(4.0),
+            loop_len_frames,
+            lead_pad_frames,
+            wrap_count: wraps,
+            force_takes: false,
+        });
+        r
+    }
+
+    #[test]
+    fn no_wrap_is_not_a_cycle_recording() {
+        // Stopping before the transport ever wraps stays an ordinary single recording — the whole
+        // point of triggering on the wrap rather than on the cycle region merely existing.
+        let r = rec(vec![1.0; 10], 4, 0, 0);
+        assert!(r.slice_takes().is_none());
+    }
+
+    #[test]
+    fn force_takes_makes_a_partial_pass_a_take() {
+        // Recording over a region that already holds takes: this run is another take however short
+        // it ran, so it's cut and padded like any partial pass rather than landing as a separate
+        // overlapping clip. Two real frames of an 8-frame region -> one take, silence for the rest.
+        let takes = rec_forced(vec![1.0, 2.0], 8, 0, 0)
+            .slice_takes()
+            .expect("forced takes");
+        assert_eq!(takes.len(), 1);
+        assert_eq!(takes[0], vec![1.0, 2.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0]);
+    }
+
+    #[test]
+    fn takes_are_cut_at_exact_loop_multiples() {
+        // 12 frames of audio, 4-frame loop, started at the region start => 3 clean takes.
+        let audio: Vec<f32> = (1..=12).map(|i| i as f32).collect();
+        let takes = rec(audio, 4, 0, 2).slice_takes().expect("cycle takes");
+        assert_eq!(takes.len(), 3);
+        assert_eq!(takes[0], vec![1.0, 2.0, 3.0, 4.0]);
+        assert_eq!(takes[1], vec![5.0, 6.0, 7.0, 8.0]);
+        assert_eq!(takes[2], vec![9.0, 10.0, 11.0, 12.0]);
+    }
+
+    #[test]
+    fn punch_in_pads_the_head_of_take_one() {
+        // Punched in 2 frames into the region: take 1 gets 2 frames of silence at the FRONT so it
+        // still spans the whole region and lines up with every other take.
+        let audio: Vec<f32> = (1..=10).map(|i| i as f32).collect();
+        let takes = rec(audio, 4, 2, 2).slice_takes().expect("cycle takes");
+        assert_eq!(takes.len(), 3);
+        assert_eq!(takes[0], vec![0.0, 0.0, 1.0, 2.0]);
+        assert_eq!(takes[1], vec![3.0, 4.0, 5.0, 6.0]);
+        assert_eq!(takes[2], vec![7.0, 8.0, 9.0, 10.0]);
+    }
+
+    #[test]
+    fn stopping_mid_pass_pads_the_tail_of_the_last_take() {
+        // 13 frames, 8-frame loop => the second take holds 5 real frames (50 ms at 100 Hz, right at
+        // the keep threshold) and 3 of silence.
+        let audio: Vec<f32> = (1..=13).map(|i| i as f32).collect();
+        let takes = rec(audio, 8, 0, 1).slice_takes().expect("cycle takes");
+        assert_eq!(takes.len(), 2);
+        assert_eq!(takes[1], vec![9.0, 10.0, 11.0, 12.0, 13.0, 0.0, 0.0, 0.0]);
+    }
+
+    #[test]
+    fn every_take_is_the_same_length() {
+        // Uniform length is the invariant comping-via-split depends on.
+        let audio: Vec<f32> = (1..=23).map(|i| i as f32).collect();
+        let takes = rec(audio, 8, 3, 3).slice_takes().expect("cycle takes");
+        assert!(takes.iter().all(|t| t.len() == 8), "takes must be uniform");
+    }
+
+    #[test]
+    fn a_sliver_of_a_final_take_is_dropped() {
+        // Stopped 1 frame (10 ms at 100 Hz) after the wrap — below the 50 ms floor, so that stub of
+        // a take is a stop artifact and goes.
+        let audio: Vec<f32> = (1..=9).map(|i| i as f32).collect();
+        let takes = rec(audio, 8, 0, 1).slice_takes().expect("cycle takes");
+        assert_eq!(takes.len(), 1, "a 10ms tail take should be dropped");
+        assert_eq!(takes[0].len(), 8);
+    }
+
+    #[test]
+    fn a_full_final_take_is_never_dropped() {
+        // Regression: the sliver rule must only fire on a PARTIAL pass. A pass that filled the
+        // region is a real take however short the region is — an earlier version compared a full
+        // take's duration to the floor and silently ate it.
+        let audio: Vec<f32> = (1..=8).map(|i| i as f32).collect();
+        let takes = rec(audio, 4, 0, 1).slice_takes().expect("cycle takes");
+        assert_eq!(takes.len(), 2, "both passes filled the region");
+        assert_eq!(takes[1], vec![5.0, 6.0, 7.0, 8.0]);
+    }
+}
+
+#[cfg(test)]
+mod midi_cycle_tests {
+    use super::*;
+
+    /// A MIDI recording anchored at the region start (beat 0), region 4 beats long.
+    fn rec() -> MidiRecordingState {
+        MidiRecordingState::new(0, 0, Beats(0.0))
+    }
+
+    /// One pass of the transport around a 4-beat region.
+    fn wrap(r: &mut MidiRecordingState) {
+        r.wrap_at_cycle(Beats(4.0), Beats(0.0));
+    }
+
+    #[test]
+    fn notes_are_bucketed_by_the_pass_they_were_played_in() {
+        let mut r = rec();
+        r.note_on(60, 100, Beats(1.0));
+        r.note_off(60, Beats(2.0)); // pass 0
+        wrap(&mut r);
+        r.note_on(62, 100, Beats(1.0));
+        r.note_off(62, Beats(2.0)); // pass 1
+        wrap(&mut r);
+        r.note_on(64, 100, Beats(1.0));
+        r.note_off(64, Beats(2.0)); // pass 2
+
+        assert_eq!(r.pass_count(), 3);
+        let by_pass = r.notes_by_pass(r.pass_count());
+        let pitches: Vec<Vec<u8>> = by_pass
+            .iter()
+            .map(|p| p.iter().map(|n| n.1).collect())
+            .collect();
+        assert_eq!(pitches, vec![vec![60], vec![62], vec![64]]);
+    }
+
+    #[test]
+    fn a_note_held_across_a_wrap_splits_between_the_two_passes() {
+        // The key is still down at the boundary: the sounding half belongs to the pass that's
+        // ending, and the re-opened half to the pass that's beginning. Getting the pass bump on the
+        // wrong side of close_active_notes would file the whole note under one pass.
+        let mut r = rec();
+        r.note_on(60, 100, Beats(3.0));
+        wrap(&mut r); // still held
+        r.note_off(60, Beats(1.0)); // released 1 beat into the next pass
+
+        assert_eq!(r.pass_count(), 2);
+        let by_pass = r.notes_by_pass(r.pass_count());
+        assert_eq!(by_pass[0].len(), 1, "the held half lands in the pass that ended");
+        assert_eq!(by_pass[1].len(), 1, "the re-opened half lands in the next pass");
+        // Pass 0's half runs from beat 3 to the region end at 4.
+        assert_eq!(by_pass[0][0].0, Beats(3.0));
+        assert_eq!(by_pass[0][0].3, Beats(1.0));
+        // Pass 1's half starts at the region start and runs to the release.
+        assert_eq!(by_pass[1][0].0, Beats(0.0));
+        assert_eq!(by_pass[1][0].3, Beats(1.0));
+    }
+
+    #[test]
+    fn a_silent_interior_pass_still_yields_an_empty_take() {
+        // Take N in the folder must be pass N on the transport, even if nothing was played — else
+        // the take numbering silently shifts under the user.
+        let mut r = rec();
+        r.note_on(60, 100, Beats(1.0));
+        r.note_off(60, Beats(2.0)); // pass 0
+        wrap(&mut r);
+        wrap(&mut r); // pass 1: played nothing
+        r.note_on(64, 100, Beats(1.0));
+        r.note_off(64, Beats(2.0)); // pass 2
+
+        let by_pass = r.notes_by_pass(r.pass_count());
+        assert_eq!(by_pass.len(), 3);
+        assert_eq!(by_pass[1].len(), 0, "the silent pass is still take 2");
+        assert_eq!(by_pass[2][0].1, 64);
+    }
+
+    #[test]
+    fn a_trailing_empty_pass_is_dropped() {
+        // Hitting stop shortly after a wrap leaves a pass you never played into. That's a stop
+        // artifact, not a take — unlike a silent pass in the middle, which was a deliberate rest.
+        let mut r = rec();
+        r.note_on(60, 100, Beats(1.0));
+        r.note_off(60, Beats(2.0)); // pass 0
+        wrap(&mut r);
+        r.note_on(62, 100, Beats(1.0));
+        r.note_off(62, Beats(2.0)); // pass 1
+        wrap(&mut r); // pass 2 begins... and the user hits stop
+
+        assert_eq!(r.pass_count(), 3);
+        let by_pass = r.notes_by_pass(r.pass_count());
+        assert_eq!(by_pass.len(), 2, "the empty trailing pass is not a take");
+    }
+
+    #[test]
+    fn an_empty_recording_still_yields_one_take() {
+        let mut r = rec();
+        wrap(&mut r);
+        wrap(&mut r);
+        assert_eq!(r.notes_by_pass(r.pass_count()).len(), 1);
+    }
 }

daw-backend/src/audio/track.rs

@@ -1,6 +1,6 @@
 use super::automation::{AutomationLane, AutomationLaneId, ParameterId};
 use super::clip::{AudioClipInstance, AudioClipInstanceId};
-use super::midi::{MidiClipInstance, MidiClipInstanceId, MidiEvent};
+use super::midi::{MidiClipId, MidiClipInstance, MidiClipInstanceId, MidiEvent};
 use super::midi_pool::MidiClipPool;
 use super::node_graph::AudioGraph;
 use super::node_graph::nodes::{AudioInputNode, AudioOutputNode};
@@ -43,6 +43,13 @@ pub struct RenderContext<'a> {
     /// Used after pause/stop to route note-off tails through the normal group hierarchy
     /// without re-triggering notes from clips at the paused position.
     pub live_only: bool,
+    /// The MIDI recording in progress, if any: (track being recorded to, clip being recorded into).
+    ///
+    /// On that track, every OTHER clip is silenced for the duration of the recording. You're playing
+    /// a part into this region — hearing what's already there (a previous take, say) fighting with
+    /// what you're playing now is just noise. The clip being recorded into is exempt, because in
+    /// merge mode that's exactly what you DO want to hear: the overdub you've been building up.
+    pub recording_midi: Option<(TrackId, MidiClipId)>,
 }
 
 impl<'a> RenderContext<'a> {
@@ -61,6 +68,7 @@ impl<'a> RenderContext<'a> {
             buffer_size,
             time_stretch: 1.0,
             live_only: false,
+            recording_midi: None,
         }
     }
 
@@ -864,9 +872,21 @@ impl MidiTrack {
             let playhead_beats = ctx.playhead_beats();
             let buffer_end_beats = ctx.buffer_end_beats();
 
+            // While recording into this track, every clip EXCEPT the one being recorded into is
+            // silenced. Otherwise a take folder already sitting in the cycle region would play its
+            // active take underneath you on every pass, fighting the part you're trying to record.
+            // The recording clip itself is exempt: in merge mode that's the overdub monitoring.
+            let muted_clip = match ctx.recording_midi {
+                Some((track_id, clip_id)) if track_id == self.id => Some(clip_id),
+                _ => None,
+            };
+
             // Collect MIDI events from all clip instances that overlap with current beat range
             let mut currently_active = HashSet::new();
             for instance in &self.clip_instances {
+                if muted_clip.is_some_and(|recording| instance.clip_id != recording) {
+                    continue;
+                }
                 if instance.overlaps_range(playhead_beats, buffer_end_beats) {
                     currently_active.insert(instance.id);
                 }

daw-backend/src/command/mod.rs

@@ -1,3 +1,3 @@
 pub mod types;
 
-pub use types::{AudioEvent, Command, MidiClipData, OscilloscopeData, Query, QueryResponse};
+pub use types::{AudioEvent, Command, MidiClipData, OscilloscopeData, Query, QueryResponse, TrimRange};

daw-backend/src/command/types.rs

@@ -8,6 +8,21 @@ use crate::audio::node_graph::nodes::LoopMode;
 use crate::io::WaveformPeak;
 use crate::time::{Beats, Seconds};
 
+/// A clip's internal (content) boundaries, tagged with the domain they're measured in.
+///
+/// A clip's content time is SECONDS for sampled audio but BEATS for MIDI — the same polymorphism
+/// `ClipInstance::trim_start`/`trim_end` carry. Passing these as bare `f64`s meant the caller and
+/// the engine could disagree about the unit with nothing to catch it: an audio trim of "1.0" was
+/// once stored as `Beats(1.0)` for the clip's external duration, so a 1-second split played back as
+/// half a second at 120 BPM. Tagging the domain makes that a type error instead of a bug report.
+#[derive(Debug, Clone, Copy, PartialEq)]
+pub enum TrimRange {
+    /// Sampled-audio content time.
+    Seconds { start: Seconds, end: Seconds },
+    /// MIDI content time.
+    Beats { start: Beats, end: Beats },
+}
+
 /// Commands sent from UI/control thread to audio thread
 #[derive(Debug, Clone)]
 pub enum Command {
@@ -19,7 +34,7 @@ pub enum Command {
     /// Pause playback (maintains position)
     Pause,
     /// Seek to a specific position in seconds
-    Seek(f64),
+    Seek(Seconds),
 
     // Track management commands
     /// Set track volume (0.0 = silence, 1.0 = unity gain)
@@ -31,13 +46,12 @@ pub enum Command {
 
     // Clip management commands
     /// Move a clip to a new timeline position (track_id, clip_id, new_external_start)
-    MoveClip(TrackId, ClipId, f64),
+    MoveClip(TrackId, ClipId, Beats),
-    /// Trim a clip's internal boundaries (track_id, clip_id, new_internal_start, new_internal_end)
+    /// Trim a clip's internal boundaries — which portion of the source content is used.
-    /// This changes which portion of the source content is used
+    TrimClip(TrackId, ClipId, TrimRange),
-    TrimClip(TrackId, ClipId, f64, f64),
     /// Extend/shrink a clip's external duration (track_id, clip_id, new_external_duration)
     /// If duration > internal duration, the clip will loop
-    ExtendClip(TrackId, ClipId, f64),
+    ExtendClip(TrackId, ClipId, Beats),
 
     // Metatrack management commands
     /// Create a new metatrack with a name and optional parent group
@@ -53,15 +67,15 @@ pub enum Command {
     SetTimeStretch(TrackId, f32),
     /// Set metatrack time offset in seconds (track_id, offset)
     /// Positive = shift content later, negative = shift earlier
-    SetOffset(TrackId, f64),
+    SetOffset(TrackId, Seconds),
     /// Set metatrack pitch shift in semitones (track_id, semitones) - for future use
     SetPitchShift(TrackId, f32),
     /// Set metatrack trim start in seconds (track_id, trim_start)
     /// Children won't hear content before this point
-    SetTrimStart(TrackId, f64),
+    SetTrimStart(TrackId, Seconds),
     /// Set metatrack trim end in seconds (track_id, trim_end)
     /// None means no end trim
-    SetTrimEnd(TrackId, Option<f64>),
+    SetTrimEnd(TrackId, Option<Seconds>),
 
     // Audio track commands
     /// Create a new audio track with a name and optional parent group
@@ -80,14 +94,14 @@ pub enum Command {
     /// Add a MIDI clip to the pool without placing it on a track
     AddMidiClipToPool(MidiClip),
     /// Create a new MIDI clip on a track (track_id, start_time, duration)
-    CreateMidiClip(TrackId, f64, f64),
+    CreateMidiClip(TrackId, Beats, Beats),
     /// Add a MIDI note to a clip (track_id, clip_id, time_offset, note, velocity, duration)
-    AddMidiNote(TrackId, MidiClipId, f64, u8, u8, f64),
+    AddMidiNote(TrackId, MidiClipId, Beats, u8, u8, Beats),
     /// Add a pre-loaded MIDI clip to a track (track_id, clip, start_time)
-    AddLoadedMidiClip(TrackId, MidiClip, f64),
+    AddLoadedMidiClip(TrackId, MidiClip, Beats),
     /// Update MIDI clip notes (track_id, clip_id, notes: Vec<(start_time, note, velocity, duration)>)
     /// NOTE: May need to switch to individual note operations if this becomes slow on clips with many notes
-    UpdateMidiClipNotes(TrackId, MidiClipId, Vec<(f64, u8, u8, f64)>),
+    UpdateMidiClipNotes(TrackId, MidiClipId, Vec<(Beats, u8, u8, Beats)>),
     /// Replace all events in a MIDI clip (track_id, clip_id, events). Used for CC/pitch bend editing.
     UpdateMidiClipEvents(TrackId, MidiClipId, Vec<MidiEvent>),
     /// Remove a MIDI clip instance from a track (track_id, instance_id) - for undo/redo support
@@ -103,9 +117,9 @@ pub enum Command {
     /// Create a new automation lane on a track (track_id, parameter_id)
     CreateAutomationLane(TrackId, ParameterId),
     /// Add an automation point to a lane (track_id, lane_id, time, value, curve)
-    AddAutomationPoint(TrackId, AutomationLaneId, f64, f32, CurveType),
+    AddAutomationPoint(TrackId, AutomationLaneId, Beats, f32, CurveType),
     /// Remove an automation point at a specific time (track_id, lane_id, time, tolerance)
-    RemoveAutomationPoint(TrackId, AutomationLaneId, f64, f64),
+    RemoveAutomationPoint(TrackId, AutomationLaneId, Beats, Beats),
     /// Clear all automation points from a lane (track_id, lane_id)
     ClearAutomationLane(TrackId, AutomationLaneId),
     /// Remove an automation lane (track_id, lane_id)
@@ -113,9 +127,24 @@ pub enum Command {
     /// Enable/disable an automation lane (track_id, lane_id, enabled)
     SetAutomationLaneEnabled(TrackId, AutomationLaneId, bool),
 
+    // Transport cycle (loop) region
+    /// Set the cycle region the transport loops over, in beats (None clears it).
+    /// Authored in beats so it survives tempo changes.
+    SetLoopRegion(Option<(Beats, Beats)>),
+    /// Enable/disable wrapping at the cycle region's end.
+    SetLoopEnabled(bool),
+    /// How a cycle MIDI recording treats its passes.
+    ///
+    /// `false` (default) = MERGE: every pass overdubs into one clip. `true` = SEPARATE TAKES: each
+    /// pass becomes its own MIDI clip, and the editor folds them into a take folder — the same shape
+    /// audio always gets.
+    SetCycleMidiSeparateTakes(bool),
+
     // Recording commands
     /// Start recording on a track (track_id, start_time)
-    StartRecording(TrackId, Beats),
+    /// (track, start_time, force_takes — cut takes even if the transport never wraps, because the
+    /// region already holds takes and this is another one)
+    StartRecording(TrackId, Beats, bool),
     /// Stop the current recording
     StopRecording,
     /// Pause the current recording
@@ -125,7 +154,8 @@ pub enum Command {
 
     // MIDI Recording commands
     /// Start MIDI recording on a track (track_id, clip_id, start_time)
-    StartMidiRecording(TrackId, MidiClipId, Beats),
+    /// (track, clip, start_time, force_takes — see [`Command::StartRecording`])
+    StartMidiRecording(TrackId, MidiClipId, Beats, bool),
     /// Stop the current MIDI recording
     StopMidiRecording,
 
@@ -237,9 +267,9 @@ pub enum Command {
 
     // Automation Input Node commands
     /// Add or update a keyframe on an AutomationInput node (track_id, node_id, time, value, interpolation, ease_out, ease_in)
-    AutomationAddKeyframe(TrackId, u32, f64, f32, String, (f32, f32), (f32, f32)),
+    AutomationAddKeyframe(TrackId, u32, Beats, f32, String, (f32, f32), (f32, f32)),
     /// Remove a keyframe from an AutomationInput node (track_id, node_id, time)
-    AutomationRemoveKeyframe(TrackId, u32, f64),
+    AutomationRemoveKeyframe(TrackId, u32, Beats),
     /// Set the display name of an AutomationInput node (track_id, node_id, name)
     AutomationSetName(TrackId, u32, String),
 
@@ -271,7 +301,7 @@ pub enum Command {
 #[derive(Debug, Clone)]
 pub enum AudioEvent {
     /// Current playback position in seconds
-    PlaybackPosition(f64),
+    PlaybackPosition(Seconds),
     /// Playback has stopped (reached end of audio)
     PlaybackStopped,
     /// Audio buffer underrun detected
@@ -292,6 +322,35 @@ pub enum AudioEvent {
     RecordingProgress(ClipId, Seconds),
     /// Recording stopped (clip_id, pool_index, waveform)
     RecordingStopped(ClipId, usize, Vec<WaveformPeak>),
+    /// A MIDI recording that wrapped the cycle region at least once, in SEPARATE TAKES mode.
+    ///
+    /// One MIDI clip per pass, in recording order. (Merge mode emits the ordinary
+    /// `MidiRecordingStopped` instead — all passes are already folded into the one clip.)
+    MidiCycleRecordingStopped {
+        track_id: TrackId,
+        /// One pool MIDI clip per pass. The first is the clip the recording started on.
+        clip_ids: Vec<MidiClipId>,
+        /// Where the takes sit on the timeline — the cycle region's start.
+        loop_start: Beats,
+        /// The region's length in beats: every take spans exactly this.
+        loop_len_beats: Beats,
+    },
+    /// A recording that wrapped the cycle region at least once, and so became multi-take.
+    ///
+    /// Each take spans the full region and they're all the same length (partial passes are padded
+    /// with silence), so the editor can promote the recording clip straight to a take folder.
+    CycleRecordingStopped {
+        clip_id: ClipId,
+        /// One entry per pass: (audio pool index, waveform peaks), in recording order.
+        takes: Vec<(usize, Vec<WaveformPeak>)>,
+        /// Where the takes sit on the timeline — the cycle region's start, not the punch-in point.
+        loop_start: Beats,
+        /// The region's length in beats (what the take folder stores as `recorded_loop_beats`).
+        loop_len_beats: Beats,
+        /// The same length in seconds — the take folder's content duration, which is seconds-domain
+        /// for audio.
+        loop_len_seconds: Seconds,
+    },
     /// Recording error (error_message)
     RecordingError(String),
     /// MIDI recording stopped (track_id, clip_id, note_count)
@@ -342,7 +401,7 @@ pub enum AudioEvent {
     WaveformChunksReady {
         pool_index: usize,
         detail_level: u8,
-        chunks: Vec<(u32, (f64, f64), Vec<WaveformPeak>)>,
+        chunks: Vec<(u32, (Seconds, Seconds), Vec<WaveformPeak>)>,
     },
 
     /// An audio file has been imported and is ready for playback.
@@ -353,7 +412,7 @@ pub enum AudioEvent {
         path: String,
         channels: u32,
         sample_rate: u32,
-        duration: f64,
+        duration: Seconds,
         format: crate::io::audio_file::AudioFormat,
     },
 
@@ -427,7 +486,7 @@ pub enum Query {
     /// Export audio to file (settings, output_path)
     ExportAudio(crate::audio::ExportSettings, std::path::PathBuf),
     /// Add a MIDI clip to a track synchronously (track_id, clip, start_time) - returns instance ID
-    AddMidiClipSync(TrackId, crate::audio::midi::MidiClip, f64),
+    AddMidiClipSync(TrackId, crate::audio::midi::MidiClip, Beats),
     /// Add a MIDI clip instance to a track synchronously (track_id, instance) - returns instance ID
     /// The clip must already exist in the MidiClipPool
     AddMidiClipInstanceSync(TrackId, crate::audio::midi::MidiClipInstance),
@@ -472,16 +531,21 @@ pub struct OscilloscopeData {
 }
 
 /// MIDI clip data for serialization
+///
+/// `Beats`/`Seconds` are `#[serde(transparent)]`, so naming the domain here costs nothing on disk —
+/// the `.beam` still holds a plain number.
 #[derive(Debug, Clone, serde::Serialize, serde::Deserialize)]
 pub struct MidiClipData {
-    pub duration: f64,
+    /// MIDI content length is musical, so beats.
+    pub duration: Beats,
     pub events: Vec<crate::audio::midi::MidiEvent>,
 }
 
 /// Automation keyframe data for serialization
 #[derive(Debug, Clone, serde::Serialize, serde::Deserialize)]
 pub struct AutomationKeyframeData {
-    pub time: f64,
+    /// Automation x-axes are all beats.
+    pub time: Beats,
     pub value: f32,
     pub interpolation: String,
     pub ease_out: (f32, f32),
@@ -518,7 +582,7 @@ pub enum QueryResponse {
     /// Pool waveform data
     PoolWaveform(Result<Vec<crate::io::WaveformPeak>, String>),
     /// Pool file info (duration, sample_rate, channels)
-    PoolFileInfo(Result<(f64, u32, u32), String>),
+    PoolFileInfo(Result<(Seconds, u32, u32), String>),
     /// Audio exported
     AudioExported(Result<(), String>),
     /// MIDI clip instance added (returns instance ID)

daw-backend/src/lib.rs

@@ -20,7 +20,7 @@ pub use audio::{
     TrackNode,
 };
 pub use audio::node_graph::{GraphPreset, AudioGraph, PresetMetadata, SerializedConnection, SerializedNode};
-pub use time::{Beats, Seconds};
+pub use time::{Beats, ContentTime, Seconds};
 pub use tempo_map::{TempoEntry, TempoInterpolation, TempoMap, beats_to_seconds_stack, seconds_to_beats_stack};
 pub use command::{AudioEvent, Command, OscilloscopeData};
 pub use command::types::AutomationKeyframeData;

daw-backend/src/time.rs

@@ -16,6 +16,50 @@ pub struct Beats(pub f64);
 #[serde(transparent)]
 pub struct Seconds(pub f64);
 
+/// A time *inside a clip's own content*, in whatever unit that clip measures content in.
+///
+/// Clip content time is domain-polymorphic: SECONDS for sampled audio, video and vector, but BEATS
+/// for MIDI (musical, so it survives tempo changes). `ClipInstance::trim_start`/`trim_end` are
+/// content times, and storing them as bare `f64`s is what let a seconds delta get added to a MIDI
+/// clip's beats trim — splitting a MIDI clip at beat 4 landed at beat 2 at 120 BPM.
+///
+/// This type is deliberately a **dead end**: it has no `.to_seconds()`, no `.to_beats()`, and no
+/// arithmetic with `Seconds` or `Beats`. Content times can be compared and combined with each other
+/// (that's domain-safe — both operands are in the same clip's domain), but the only way to get a
+/// real timeline duration out is to resolve it against the clip that knows the domain, via
+/// `AudioClip::resolve_content_time` / `Document::resolve_content_time`. So a passthrough costs
+/// nothing, and mixing domains won't compile.
+#[derive(Debug, Clone, Copy, PartialEq, PartialOrd, Default, Serialize, Deserialize)]
+#[serde(transparent)]
+pub struct ContentTime(pub f64);
+
+impl ContentTime {
+    pub const ZERO: Self = Self(0.0);
+
+    pub fn max(self, other: Self) -> Self { Self(self.0.max(other.0)) }
+    pub fn min(self, other: Self) -> Self { Self(self.0.min(other.0)) }
+
+    /// The raw magnitude, with the domain discarded.
+    ///
+    /// Only for code that is *already* working in this clip's content domain (trim arithmetic,
+    /// serialization, drawing a waveform whose x-axis is the clip's own content). If you are about
+    /// to combine this with a timeline position, resolve it against the clip instead.
+    pub fn raw(self) -> f64 { self.0 }
+}
+
+impl Add for ContentTime {
+    type Output = Self;
+    fn add(self, rhs: Self) -> Self { Self(self.0 + rhs.0) }
+}
+impl Sub for ContentTime {
+    type Output = Self;
+    fn sub(self, rhs: Self) -> Self { Self(self.0 - rhs.0) }
+}
+impl Rem for ContentTime {
+    type Output = Self;
+    fn rem(self, rhs: Self) -> Self { Self(self.0 % rhs.0) }
+}
+
 impl Beats {
     pub const ZERO: Self = Self(0.0);
 

daw-backend/src/tui/mod.rs

@@ -556,7 +556,7 @@ pub fn run_tui(
             while let Ok(event) = rx.pop() {
                 match event {
                     AudioEvent::PlaybackPosition(pos) => {
-                        app.update_playback_position(pos);
+                        app.update_playback_position(pos.seconds_to_f64());
                     }
                     AudioEvent::PlaybackStopped => {
                         app.set_playing(false);

lightningbeam-ui/Cargo.lock

@@ -3628,7 +3628,7 @@ dependencies = [
 
 [[package]]
 name = "lightningbeam-editor"
-version = "1.0.8-alpha"
+version = "1.0.9-alpha"
 dependencies = [
  "beamdsp",
  "bytemuck",

lightningbeam-ui/lightningbeam-core/src/action.rs

@@ -47,6 +47,113 @@ pub struct BackendContext<'a> {
     // Future: pub video_controller: Option<&'a mut VideoController>,
 }
 
+impl BackendContext<'_> {
+    /// Hand a clip instance to the audio engine and record it in the instance→backend map.
+    ///
+    /// Take folders are resolved through the instance's `active_take`, so the backend gets whichever
+    /// take is selected. Returns the backend track and instance IDs, or `None` when there's nothing
+    /// to sync yet (a recording in progress, or an empty take folder).
+    ///
+    /// Lives here rather than in any one action because more than one action needs it: adding an
+    /// instance, and switching a take folder's active take (which is a remove + re-add, there being
+    /// no in-place pool-swap command). Keeping one implementation keeps the trim/duration
+    /// conversions — the easy thing to get subtly wrong, since `trim_*` is SECONDS while
+    /// `timeline_*` is BEATS — from drifting between copies.
+    pub fn add_clip_instance(
+        &mut self,
+        document: &Document,
+        layer_id: &Uuid,
+        instance: &crate::clip::ClipInstance,
+    ) -> Result<Option<(daw_backend::TrackId, BackendClipInstanceId)>, String> {
+        use crate::clip::ResolvedContent;
+
+        let clip = document
+            .get_audio_clip(&instance.clip_id)
+            .ok_or_else(|| format!("Audio clip {} not found", instance.clip_id))?;
+
+        let track_id = *self
+            .layer_to_track_map
+            .get(layer_id)
+            .ok_or_else(|| format!("Layer {} not mapped to backend track", layer_id))?;
+
+        let resolved = instance.resolve(clip);
+        let content = clip.content_duration();
+        let internal_start = instance.trim_start;
+        let internal_end = instance
+            .trim_end
+            .unwrap_or(daw_backend::ContentTime(content.native()));
+        let start_time = instance.timeline_start;
+
+        // How long the clip occupies the timeline, in BEATS. `effective_duration_beats` resolves the
+        // content window in the clip's own domain — beats content carries over directly, wall-clock
+        // content converts at the clip's position — so neither kind can be read as the other here.
+        let effective_duration = instance.effective_duration_beats(content, document.tempo_map());
+
+        let controller = self
+            .audio_controller
+            .as_mut()
+            .ok_or_else(|| "Audio controller not available".to_string())?;
+
+        let backend_id = match resolved {
+            ResolvedContent::Midi { midi_clip_id } => {
+                use daw_backend::command::{Query, QueryResponse};
+
+                // MIDI content time IS beats, so the trims carry straight over.
+                let midi_instance = daw_backend::MidiClipInstance::new(
+                    0, // assigned by the backend
+                    midi_clip_id,
+                    daw_backend::Beats(internal_start.raw()),
+                    daw_backend::Beats(internal_end.raw()),
+                    start_time,
+                    effective_duration,
+                );
+
+                match controller
+                    .send_query(Query::AddMidiClipInstanceSync(track_id, midi_instance))?
+                {
+                    QueryResponse::MidiClipInstanceAdded(Ok(id)) => BackendClipInstanceId::Midi(id),
+                    QueryResponse::MidiClipInstanceAdded(Err(e)) => return Err(e),
+                    _ => return Err("Unexpected query response".to_string()),
+                }
+            }
+            ResolvedContent::Audio { audio_pool_index } => {
+                // Sampled-audio content time is SECONDS; the backend's start/duration are BEATS.
+                let id = controller.add_audio_clip(
+                    track_id,
+                    audio_pool_index,
+                    start_time,
+                    effective_duration,
+                    daw_backend::Seconds(internal_start.raw()),
+                );
+                BackendClipInstanceId::Audio(id)
+            }
+            // Nothing to sync until it has content.
+            ResolvedContent::Recording => return Ok(None),
+        };
+
+        self.clip_instance_to_backend_map
+            .insert(instance.id, backend_id);
+
+        Ok(Some((track_id, backend_id)))
+    }
+
+    /// Remove a clip instance's backend clip and drop it from the instance→backend map.
+    pub fn remove_clip_instance(
+        &mut self,
+        track_id: daw_backend::TrackId,
+        backend_id: BackendClipInstanceId,
+        instance_id: Uuid,
+    ) {
+        if let Some(controller) = self.audio_controller.as_mut() {
+            match backend_id {
+                BackendClipInstanceId::Midi(id) => controller.remove_midi_clip(track_id, id),
+                BackendClipInstanceId::Audio(id) => controller.remove_audio_clip(track_id, id),
+            }
+        }
+        self.clip_instance_to_backend_map.remove(&instance_id);
+    }
+}
+
 /// Action trait for undo/redo operations
 ///
 /// Each action must be able to execute (apply changes) and rollback (undo changes).

lightningbeam-ui/lightningbeam-core/src/actions/add_clip_instance.rs

@@ -89,10 +89,11 @@ impl Action for AddClipInstanceAction {
         // `get_clip_duration` is the content length in seconds; the placement span
         // must be beats (the timeline is beats-domain), so convert via the clip's
         // typed helper rather than treating the seconds span as beats.
-        let clip_duration = document.get_clip_duration(&self.clip_instance.clip_id)
+        // The clip's content duration in ITS OWN domain, so the trims resolve correctly for MIDI.
+        let clip_content = document.clip_trim_duration(&self.clip_instance.clip_id)
             .ok_or_else(|| format!("Clip {} not found", self.clip_instance.clip_id))?;
         let effective_duration = self.clip_instance
-            .effective_duration_beats(clip_duration, document.tempo_map());
+            .effective_duration_beats(clip_content, document.tempo_map());
 
         // Auto-adjust position for audio/video layers to avoid overlaps
         let adjusted_start = document.find_nearest_valid_position(
@@ -196,113 +197,23 @@ impl Action for AddClipInstanceAction {
             return Ok(());
         }
 
-        // Look up the clip from the document
+        // Add via the shared BackendContext helper — the same one SetActiveTakeAction uses, so
-        let clip = document
+        // the trim/duration conversions (and take-folder resolution) live in exactly one place.
-            .get_audio_clip(&self.clip_instance.clip_id)
+        if let Some((track_id, backend_id)) =
-            .ok_or_else(|| "Audio clip not found".to_string())?;
+            backend.add_clip_instance(document, &self.layer_id, &self.clip_instance)?
-
+        {
-        // Look up backend track ID from layer mapping
+            self.backend_track_id = Some(track_id);
-        let backend_track_id = backend
+            match backend_id {
-            .layer_to_track_map
+                crate::action::BackendClipInstanceId::Midi(id) => {
-            .get(&self.layer_id)
+                    self.backend_midi_instance_id = Some(id)
-            .ok_or_else(|| format!("Layer {} not mapped to backend track", self.layer_id))?;
+                }
-
+                crate::action::BackendClipInstanceId::Audio(id) => {
-        // Get audio controller
+                    self.backend_audio_instance_id = Some(id)
-        let controller = backend
-            .audio_controller
-            .as_mut()
-            .ok_or_else(|| "Audio controller not available".to_string())?;
-
-        // Handle different clip types
-        use crate::clip::AudioClipType;
-        match &clip.clip_type {
-            AudioClipType::Midi { midi_clip_id } => {
-                // Create a MIDI clip instance referencing the existing clip in the backend pool
-                // No need to add to pool again - it was added during MIDI import
-                use daw_backend::command::{Query, QueryResponse};
-
-                // Calculate internal start/end from trim parameters
-                let internal_start = self.clip_instance.trim_start;
-                let internal_end = self.clip_instance.trim_end.unwrap_or(clip.content_duration().native());
-                let external_start = self.clip_instance.timeline_start;
-
-                // Calculate external duration (for looping if timeline_duration is set).
-                // MIDI trims are beats-domain, so the fallback span is beats too.
-                let external_duration = self.clip_instance.timeline_duration
-                    .unwrap_or(daw_backend::Beats(internal_end - internal_start));
-
-                // Create MidiClipInstance
-                let instance = daw_backend::MidiClipInstance::new(
-                    0, // Instance ID will be assigned by backend
-                    *midi_clip_id,
-                    daw_backend::Beats(internal_start),
-                    daw_backend::Beats(internal_end),
-                    external_start,
-                    external_duration,
-                );
-
-                // Send query to add instance and get instance ID
-                let query = Query::AddMidiClipInstanceSync(*backend_track_id, instance);
-
-                match controller.send_query(query)? {
-                    QueryResponse::MidiClipInstanceAdded(Ok(instance_id)) => {
-                        self.backend_track_id = Some(*backend_track_id);
-                        self.backend_midi_instance_id = Some(instance_id);
-
-                        // Add to global clip instance mapping
-                        backend.clip_instance_to_backend_map.insert(
-                            self.clip_instance.id,
-                            crate::action::BackendClipInstanceId::Midi(instance_id)
-                        );
-
-                        Ok(())
-                    }
-                    QueryResponse::MidiClipInstanceAdded(Err(e)) => Err(e),
-                    _ => Err("Unexpected query response".to_string()),
                 }
             }
-            AudioClipType::Sampled { audio_pool_index } => {
-                // `trim_*` / `clip.duration` are in SECONDS (audio content time),
-                // while `timeline_*` and the backend's `duration` are in BEATS.
-                let internal_start = self.clip_instance.trim_start;
-                let internal_end = self.clip_instance.trim_end.unwrap_or(clip.content_duration().native());
-                let start_time = self.clip_instance.timeline_start;
-                // `effective_duration` is in BEATS. When `timeline_duration` is set
-                // it already is; otherwise the clip occupies its natural content
-                // length, so convert that seconds-span to beats at the clip's start
-                // (NOT `internal_end - internal_start`, which is seconds — that was
-                // the seconds-as-beats bug that made clips stop early off 60 BPM).
-                let effective_duration = self.clip_instance.timeline_duration.unwrap_or_else(|| {
-                    let tempo_map = document.tempo_map();
-                    let content_secs = daw_backend::Seconds(internal_end - internal_start);
-                    tempo_map.seconds_to_beats(tempo_map.beats_to_seconds(start_time) + content_secs)
-                        - start_time
-                });
-
-                let instance_id = controller.add_audio_clip(
-                    *backend_track_id,
-                    *audio_pool_index,
-                    start_time,
-                    effective_duration,
-                    daw_backend::Seconds(internal_start),
-                );
-
-                self.backend_track_id = Some(*backend_track_id);
-                self.backend_audio_instance_id = Some(instance_id);
-
-                // Add to global clip instance mapping
-                backend.clip_instance_to_backend_map.insert(
-                    self.clip_instance.id,
-                    crate::action::BackendClipInstanceId::Audio(instance_id)
-                );
-
-                Ok(())
-            }
-            AudioClipType::Recording => {
-                // Recording clips are not synced to backend until finalized
-                Ok(())
-            }
         }
+
+        Ok(())
     }
 
     fn rollback_backend(&mut self, backend: &mut BackendContext, _document: &Document) -> Result<(), String> {

lightningbeam-ui/lightningbeam-core/src/actions/append_takes.rs

@@ -0,0 +1,141 @@
+//! Append freshly-recorded takes to an existing take folder.
+//!
+//! Cycle-recording over a region that already holds a take folder should *add* to that folder, not
+//! drop a second clip on top of it. Otherwise the takes from your second attempt are stranded in a
+//! separate, overlapping clip and you can't audition them against the first.
+//!
+//! The recorded content already exists in the backend pools by the time this runs (the engine put it
+//! there at stop), so this action only touches the document — plus the one backend clip the instance
+//! plays, which has to be repointed at the newly-active take.
+
+use crate::action::{Action, BackendClipInstanceId, BackendContext};
+use crate::clip::AudioTake;
+use crate::document::Document;
+use crate::layer::AnyLayer;
+use uuid::Uuid;
+
+/// Action that appends takes to an instance's take list and selects the last of them.
+pub struct AppendTakesAction {
+    layer_id: Uuid,
+    /// The instance whose take list is being extended (and whose active take changes).
+    instance_id: Uuid,
+    /// The takes to add, in recording order.
+    new_takes: Vec<AudioTake>,
+
+    // Stored during execute for rollback.
+    old_take_count: usize,
+    old_active_take: Option<usize>,
+    executed: bool,
+}
+
+impl AppendTakesAction {
+    pub fn new(layer_id: Uuid, instance_id: Uuid, new_takes: Vec<AudioTake>) -> Self {
+        Self {
+            layer_id,
+            instance_id,
+            new_takes,
+            old_take_count: 0,
+            old_active_take: None,
+            executed: false,
+        }
+    }
+
+    /// Swap the instance's backend clip to whatever take the document now says is active.
+    ///
+    /// Same remove + re-add as `SetActiveTakeAction` — there's no in-place pool-swap command.
+    fn resync(&self, backend: &mut BackendContext, document: &Document) -> Result<(), String> {
+        let instance = document
+            .get_layer(&self.layer_id)
+            .and_then(|l| match l {
+                AnyLayer::Audio(al) => al.clip_instances.iter().find(|ci| ci.id == self.instance_id),
+                _ => None,
+            })
+            .cloned()
+            .ok_or_else(|| format!("Clip instance {} not found", self.instance_id))?;
+
+        let existing: Option<BackendClipInstanceId> = backend
+            .clip_instance_to_backend_map
+            .get(&self.instance_id)
+            .copied();
+        let track_id = backend.layer_to_track_map.get(&self.layer_id).copied();
+        if let (Some(backend_id), Some(track_id)) = (existing, track_id) {
+            backend.remove_clip_instance(track_id, backend_id, self.instance_id);
+        }
+
+        backend.add_clip_instance(document, &self.layer_id, &instance)?;
+        Ok(())
+    }
+}
+
+impl Action for AppendTakesAction {
+    fn execute(&mut self, document: &mut Document) -> Result<(), String> {
+        let layer = document
+            .get_layer_mut(&self.layer_id)
+            .ok_or_else(|| format!("Layer {} not found", self.layer_id))?;
+        let AnyLayer::Audio(audio_layer) = layer else {
+            return Err("Takes only exist on audio layers".to_string());
+        };
+        let instance = audio_layer
+            .clip_instances
+            .iter_mut()
+            .find(|ci| ci.id == self.instance_id)
+            .ok_or_else(|| format!("Clip instance {} not found", self.instance_id))?;
+
+        // Only record the pre-state on the first execute; a redo must not overwrite it with the
+        // post-state left behind by the previous run.
+        if !self.executed {
+            self.old_take_count = instance.takes.len();
+            self.old_active_take = instance.active_take;
+        }
+
+        // Number the new takes on from what's already there. Existing names are left alone — the
+        // user may well have renamed them, and renumbering would clobber that.
+        let base = instance.takes.len();
+        for (i, take) in self.new_takes.iter().enumerate() {
+            let mut take = take.clone();
+            if take.name.is_empty() {
+                take.name = format!("Take {}", base + i + 1);
+            }
+            instance.takes.push(take);
+        }
+
+        // Land on the take just recorded, GarageBand-style.
+        instance.active_take = Some(instance.takes.len() - 1);
+        self.executed = true;
+        Ok(())
+    }
+
+    fn rollback(&mut self, document: &mut Document) -> Result<(), String> {
+        if let Some(AnyLayer::Audio(audio_layer)) = document.get_layer_mut(&self.layer_id) {
+            if let Some(instance) = audio_layer
+                .clip_instances
+                .iter_mut()
+                .find(|ci| ci.id == self.instance_id)
+            {
+                instance.takes.truncate(self.old_take_count);
+                instance.active_take = self.old_active_take;
+            }
+        }
+        Ok(())
+    }
+
+    fn description(&self) -> String {
+        format!("Record {} take(s)", self.new_takes.len())
+    }
+
+    fn execute_backend(
+        &mut self,
+        backend: &mut BackendContext,
+        document: &Document,
+    ) -> Result<(), String> {
+        self.resync(backend, document)
+    }
+
+    fn rollback_backend(
+        &mut self,
+        backend: &mut BackendContext,
+        document: &Document,
+    ) -> Result<(), String> {
+        self.resync(backend, document)
+    }
+}

lightningbeam-ui/lightningbeam-core/src/actions/loop_clip_instances.rs

@@ -91,7 +91,7 @@ impl Action for LoopClipInstancesAction {
 
 impl LoopClipInstancesAction {
     fn sync_backend(&self, backend: &mut crate::action::BackendContext, document: &Document, rollback: bool) -> Result<(), String> {
-        use crate::clip::AudioClipType;
+        use crate::clip::ResolvedContent;
 
         let controller = match backend.audio_controller.as_mut() {
             Some(c) => c,
@@ -128,26 +128,22 @@ impl LoopClipInstancesAction {
                     (new_dur, new_lb)
                 };
 
-                let content_window = {
+                // Natural content length as a beats span (the fallback when no explicit
-                    let trim_end = instance.trim_end.unwrap_or(clip.content_duration().native());
+                // timeline_duration is set). Resolved in the clip's own domain, so MIDI's beats
-                    (trim_end - instance.trim_start).max(0.0) // seconds
+                // content carries over directly rather than being read as seconds.
-                };
+                let content_window_beats = instance.effective_duration_beats(
-                // Natural content length as a beats span at the clip's start (the
+                    clip.content_duration(),
-                // fallback when no explicit timeline_duration is set).
+                    document.tempo_map(),
-                let tempo_map = document.tempo_map();
+                );
-                let content_window_beats = tempo_map.seconds_to_beats(
-                    tempo_map.beats_to_seconds(instance.timeline_start)
-                        + daw_backend::Seconds(content_window),
-                ) - instance.timeline_start;
                 let right_duration = target_duration.unwrap_or(content_window_beats);
                 let left_duration = target_loop_before.unwrap_or(daw_backend::Beats::ZERO);
                 let external_duration = left_duration + right_duration;
                 let external_start = instance.timeline_start - left_duration;
 
                 let get_backend_clip_id = |inst_id: &Uuid| -> Result<u32, String> {
-                    match &clip.clip_type {
+                    match &instance.resolve(clip) {
-                        AudioClipType::Midi { midi_clip_id } => Ok(*midi_clip_id),
+                        ResolvedContent::Midi { midi_clip_id } => Ok(*midi_clip_id),
-                        AudioClipType::Sampled { .. } => {
+                        ResolvedContent::Audio { .. } => {
                             let backend_id = backend.clip_instance_to_backend_map.get(inst_id)
                                 .ok_or_else(|| format!("Clip instance {} not mapped to backend", inst_id))?;
                             match backend_id {
@@ -155,7 +151,7 @@ impl LoopClipInstancesAction {
                                 _ => Err("Expected audio instance ID for sampled clip".to_string()),
                             }
                         }
-                        AudioClipType::Recording => Err("Cannot sync recording clip".to_string()),
+                        ResolvedContent::Recording => Err("Cannot sync recording clip".to_string()),
                     }
                 };
 

lightningbeam-ui/lightningbeam-core/src/actions/manage_takes.rs

@@ -0,0 +1,419 @@
+//! Take management: delete and rename the takes on a clip instance.
+//!
+//! Takes live on the INSTANCE, so both of these are naturally scoped to the one the user clicked —
+//! deleting a take from one half of a comped split leaves the other half's list alone.
+
+use crate::action::{Action, BackendClipInstanceId, BackendContext};
+use crate::clip::{AudioTake, ClipInstance};
+use crate::document::Document;
+use crate::layer::AnyLayer;
+use uuid::Uuid;
+
+/// The instance a take action targets, looked up mutably.
+fn instance_mut<'a>(
+    document: &'a mut Document,
+    layer_id: &Uuid,
+    instance_id: &Uuid,
+) -> Result<&'a mut ClipInstance, String> {
+    let layer = document
+        .get_layer_mut(layer_id)
+        .ok_or_else(|| format!("Layer {} not found", layer_id))?;
+    let AnyLayer::Audio(audio_layer) = layer else {
+        return Err("Takes only exist on audio layers".to_string());
+    };
+    audio_layer
+        .clip_instances
+        .iter_mut()
+        .find(|ci| ci.id == *instance_id)
+        .ok_or_else(|| format!("Clip instance {} not found", instance_id))
+}
+
+/// Swap an instance's backend clip to whatever take the document now says is active.
+///
+/// The same remove + re-add as `SetActiveTakeAction` — there's no in-place pool-swap command.
+fn resync(
+    backend: &mut BackendContext,
+    document: &Document,
+    layer_id: &Uuid,
+    instance_id: &Uuid,
+) -> Result<(), String> {
+    let instance = document
+        .get_layer(layer_id)
+        .and_then(|l| match l {
+            AnyLayer::Audio(al) => al.clip_instances.iter().find(|ci| ci.id == *instance_id),
+            _ => None,
+        })
+        .cloned()
+        .ok_or_else(|| format!("Clip instance {} not found", instance_id))?;
+
+    let existing: Option<BackendClipInstanceId> = backend
+        .clip_instance_to_backend_map
+        .get(instance_id)
+        .copied();
+    let track_id = backend.layer_to_track_map.get(layer_id).copied();
+    if let (Some(backend_id), Some(track_id)) = (existing, track_id) {
+        backend.remove_clip_instance(track_id, backend_id, *instance_id);
+    }
+
+    backend.add_clip_instance(document, layer_id, &instance)?;
+    Ok(())
+}
+
+/// Remove a take from an instance's take list.
+///
+/// The take's recorded audio/MIDI stays in the backend pool — undo has to be able to put it back,
+/// and other instances (the other half of a split, say) may still be playing it.
+pub struct DeleteTakeAction {
+    layer_id: Uuid,
+    instance_id: Uuid,
+    take_index: usize,
+
+    // Stored during execute for rollback.
+    removed: Option<AudioTake>,
+    old_active_take: Option<usize>,
+}
+
+impl DeleteTakeAction {
+    pub fn new(layer_id: Uuid, instance_id: Uuid, take_index: usize) -> Self {
+        Self {
+            layer_id,
+            instance_id,
+            take_index,
+            removed: None,
+            old_active_take: None,
+        }
+    }
+}
+
+impl Action for DeleteTakeAction {
+    fn execute(&mut self, document: &mut Document) -> Result<(), String> {
+        let instance = instance_mut(document, &self.layer_id, &self.instance_id)?;
+
+        if self.take_index >= instance.takes.len() {
+            return Err(format!("Take {} does not exist", self.take_index + 1));
+        }
+        // An instance with no takes at all would fall back to the clip's own content, which for a
+        // cycle recording is a take we may just have deleted. Refuse rather than strand it.
+        if instance.takes.len() == 1 {
+            return Err("Can't delete the only take".to_string());
+        }
+
+        self.old_active_take = instance.active_take;
+        self.removed = Some(instance.takes.remove(self.take_index));
+
+        // Everything above the removed take shifts down one, so the selection has to move with it.
+        // Deleting the *active* take lands on the one that took its place (or the new last take, if
+        // it was at the end) — that keeps the clip sounding rather than silently picking take 1.
+        let active = instance.active_take.unwrap_or(0);
+        instance.active_take = Some(if active > self.take_index {
+            active - 1
+        } else if active == self.take_index {
+            self.take_index.min(instance.takes.len() - 1)
+        } else {
+            active
+        });
+
+        Ok(())
+    }
+
+    fn rollback(&mut self, document: &mut Document) -> Result<(), String> {
+        let Some(take) = self.removed.take() else {
+            return Ok(());
+        };
+        let instance = instance_mut(document, &self.layer_id, &self.instance_id)?;
+        let at = self.take_index.min(instance.takes.len());
+        instance.takes.insert(at, take);
+        instance.active_take = self.old_active_take;
+        Ok(())
+    }
+
+    fn description(&self) -> String {
+        format!("Delete take {}", self.take_index + 1)
+    }
+
+    fn execute_backend(
+        &mut self,
+        backend: &mut BackendContext,
+        document: &Document,
+    ) -> Result<(), String> {
+        resync(backend, document, &self.layer_id, &self.instance_id)
+    }
+
+    fn rollback_backend(
+        &mut self,
+        backend: &mut BackendContext,
+        document: &Document,
+    ) -> Result<(), String> {
+        resync(backend, document, &self.layer_id, &self.instance_id)
+    }
+}
+
+/// Throw away every take except the one that's playing.
+///
+/// The tidy-up once you've picked your keeper. Scoped to this instance, so on a comped split it
+/// prunes the half you clicked and leaves the other half's alternatives intact.
+pub struct DeleteUnusedTakesAction {
+    layer_id: Uuid,
+    instance_id: Uuid,
+
+    // Stored during execute for rollback.
+    old_takes: Vec<AudioTake>,
+    old_active_take: Option<usize>,
+}
+
+impl DeleteUnusedTakesAction {
+    pub fn new(layer_id: Uuid, instance_id: Uuid) -> Self {
+        Self {
+            layer_id,
+            instance_id,
+            old_takes: Vec::new(),
+            old_active_take: None,
+        }
+    }
+}
+
+impl Action for DeleteUnusedTakesAction {
+    fn execute(&mut self, document: &mut Document) -> Result<(), String> {
+        let instance = instance_mut(document, &self.layer_id, &self.instance_id)?;
+        if instance.takes.len() < 2 {
+            return Err("Nothing to delete".to_string());
+        }
+
+        let keep = instance.active_take_index();
+        self.old_takes = instance.takes.clone();
+        self.old_active_take = instance.active_take;
+
+        let kept = instance.takes.remove(keep);
+        instance.takes.clear();
+        instance.takes.push(kept);
+        instance.active_take = Some(0);
+        Ok(())
+    }
+
+    fn rollback(&mut self, document: &mut Document) -> Result<(), String> {
+        let instance = instance_mut(document, &self.layer_id, &self.instance_id)?;
+        instance.takes = std::mem::take(&mut self.old_takes);
+        instance.active_take = self.old_active_take;
+        Ok(())
+    }
+
+    fn description(&self) -> String {
+        "Delete unused takes".to_string()
+    }
+
+    // The take that plays doesn't change, so the backend clip is already correct.
+}
+
+/// Rename a take. Document-only — which take *plays* doesn't change, so the backend is untouched.
+pub struct RenameTakeAction {
+    layer_id: Uuid,
+    instance_id: Uuid,
+    take_index: usize,
+    new_name: String,
+    old_name: String,
+}
+
+impl RenameTakeAction {
+    pub fn new(layer_id: Uuid, instance_id: Uuid, take_index: usize, new_name: String) -> Self {
+        Self {
+            layer_id,
+            instance_id,
+            take_index,
+            new_name,
+            old_name: String::new(),
+        }
+    }
+}
+
+impl Action for RenameTakeAction {
+    fn execute(&mut self, document: &mut Document) -> Result<(), String> {
+        let instance = instance_mut(document, &self.layer_id, &self.instance_id)?;
+        let take = instance
+            .takes
+            .get_mut(self.take_index)
+            .ok_or_else(|| format!("Take {} does not exist", self.take_index + 1))?;
+        self.old_name = std::mem::replace(&mut take.name, self.new_name.clone());
+        Ok(())
+    }
+
+    fn rollback(&mut self, document: &mut Document) -> Result<(), String> {
+        let instance = instance_mut(document, &self.layer_id, &self.instance_id)?;
+        if let Some(take) = instance.takes.get_mut(self.take_index) {
+            take.name = self.old_name.clone();
+        }
+        Ok(())
+    }
+
+    fn description(&self) -> String {
+        format!("Rename take to \"{}\"", self.new_name)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::clip::TakeContent;
+    use crate::layer::AudioLayer;
+
+    /// A document with one audio layer holding one instance with 4 takes (pools 10..13).
+    fn doc_with_takes() -> (Document, Uuid, Uuid) {
+        let mut document = Document::new("Test");
+        let clip = crate::clip::AudioClip::new_sampled("Cycle rec", 10, 2.0);
+        let clip_id = document.add_audio_clip(clip);
+
+        let mut instance = ClipInstance::new(clip_id);
+        instance.takes = (10..14)
+            .map(|pool| AudioTake {
+                name: format!("Take {}", pool - 9),
+                content: TakeContent::Audio { audio_pool_index: pool },
+            })
+            .collect();
+        let instance_id = instance.id;
+
+        let mut layer = AudioLayer::new("Layer");
+        layer.clip_instances.push(instance);
+        let layer_id = document.root.add_child(AnyLayer::Audio(layer));
+        (document, layer_id, instance_id)
+    }
+
+    fn takes_of(document: &Document, layer_id: &Uuid, instance_id: &Uuid) -> ClipInstance {
+        let AnyLayer::Audio(al) = document.get_layer(layer_id).unwrap() else { panic!() };
+        al.clip_instances.iter().find(|ci| ci.id == *instance_id).unwrap().clone()
+    }
+
+    #[test]
+    fn deleting_a_take_below_the_active_one_shifts_the_selection_down() {
+        // Everything above the removed take shifts down one, so a selection above it has to move
+        // with it — otherwise the instance silently starts playing a different take.
+        let (mut document, layer_id, instance_id) = doc_with_takes();
+        {
+            let AnyLayer::Audio(al) = document.get_layer_mut(&layer_id).unwrap() else { panic!() };
+            al.clip_instances[0].active_take = Some(3); // playing pool 13
+        }
+
+        DeleteTakeAction::new(layer_id, instance_id, 1)
+            .execute(&mut document)
+            .expect("delete");
+
+        let inst = takes_of(&document, &layer_id, &instance_id);
+        assert_eq!(inst.takes.len(), 3);
+        assert_eq!(inst.active_take, Some(2), "index shifted down with the take");
+        assert_eq!(
+            inst.takes[inst.active_take_index()].content,
+            TakeContent::Audio { audio_pool_index: 13 },
+            "still playing the same take it was",
+        );
+    }
+
+    #[test]
+    fn deleting_the_active_take_lands_on_its_replacement() {
+        // Deleting what you're listening to should hand you the take that took its place, not
+        // silently jump you back to take 1.
+        let (mut document, layer_id, instance_id) = doc_with_takes();
+        {
+            let AnyLayer::Audio(al) = document.get_layer_mut(&layer_id).unwrap() else { panic!() };
+            al.clip_instances[0].active_take = Some(1); // playing pool 11
+        }
+
+        DeleteTakeAction::new(layer_id, instance_id, 1)
+            .execute(&mut document)
+            .expect("delete");
+
+        let inst = takes_of(&document, &layer_id, &instance_id);
+        assert_eq!(inst.active_take, Some(1));
+        assert_eq!(
+            inst.takes[1].content,
+            TakeContent::Audio { audio_pool_index: 12 },
+            "the take that slid into the deleted one's place",
+        );
+    }
+
+    #[test]
+    fn deleting_the_last_take_in_the_list_steps_back() {
+        let (mut document, layer_id, instance_id) = doc_with_takes();
+        {
+            let AnyLayer::Audio(al) = document.get_layer_mut(&layer_id).unwrap() else { panic!() };
+            al.clip_instances[0].active_take = Some(3);
+        }
+
+        DeleteTakeAction::new(layer_id, instance_id, 3)
+            .execute(&mut document)
+            .expect("delete");
+
+        let inst = takes_of(&document, &layer_id, &instance_id);
+        assert_eq!(inst.active_take, Some(2), "there is no take 4 to land on");
+    }
+
+    #[test]
+    fn the_only_take_cannot_be_deleted() {
+        let (mut document, layer_id, instance_id) = doc_with_takes();
+        {
+            let AnyLayer::Audio(al) = document.get_layer_mut(&layer_id).unwrap() else { panic!() };
+            al.clip_instances[0].takes.truncate(1);
+        }
+        assert!(DeleteTakeAction::new(layer_id, instance_id, 0)
+            .execute(&mut document)
+            .is_err());
+    }
+
+    #[test]
+    fn undoing_a_delete_puts_the_take_back_where_it_was() {
+        let (mut document, layer_id, instance_id) = doc_with_takes();
+        {
+            let AnyLayer::Audio(al) = document.get_layer_mut(&layer_id).unwrap() else { panic!() };
+            al.clip_instances[0].active_take = Some(2);
+        }
+
+        let mut action = DeleteTakeAction::new(layer_id, instance_id, 1);
+        action.execute(&mut document).expect("delete");
+        action.rollback(&mut document).expect("undo");
+
+        let inst = takes_of(&document, &layer_id, &instance_id);
+        assert_eq!(inst.takes.len(), 4);
+        assert_eq!(
+            inst.takes[1].content,
+            TakeContent::Audio { audio_pool_index: 11 },
+            "restored at its original index",
+        );
+        assert_eq!(inst.active_take, Some(2), "and the selection with it");
+    }
+
+    #[test]
+    fn deleting_unused_takes_keeps_the_one_thats_playing() {
+        let (mut document, layer_id, instance_id) = doc_with_takes();
+        {
+            let AnyLayer::Audio(al) = document.get_layer_mut(&layer_id).unwrap() else { panic!() };
+            al.clip_instances[0].active_take = Some(2); // pool 12 — the keeper
+        }
+
+        let mut action = DeleteUnusedTakesAction::new(layer_id, instance_id);
+        action.execute(&mut document).expect("prune");
+
+        let inst = takes_of(&document, &layer_id, &instance_id);
+        assert_eq!(inst.takes.len(), 1);
+        assert_eq!(inst.active_take, Some(0));
+        assert_eq!(
+            inst.takes[0].content,
+            TakeContent::Audio { audio_pool_index: 12 },
+            "the take that was playing survives, and nothing else",
+        );
+
+        action.rollback(&mut document).expect("undo");
+        let inst = takes_of(&document, &layer_id, &instance_id);
+        assert_eq!(inst.takes.len(), 4);
+        assert_eq!(inst.active_take, Some(2), "back to what was playing before");
+    }
+
+    #[test]
+    fn renaming_a_take_round_trips() {
+        let (mut document, layer_id, instance_id) = doc_with_takes();
+        let mut action =
+            RenameTakeAction::new(layer_id, instance_id, 2, "The good one".to_string());
+
+        action.execute(&mut document).expect("rename");
+        assert_eq!(takes_of(&document, &layer_id, &instance_id).takes[2].name, "The good one");
+
+        action.rollback(&mut document).expect("undo");
+        assert_eq!(takes_of(&document, &layer_id, &instance_id).takes[2].name, "Take 3");
+    }
+}

lightningbeam-ui/lightningbeam-core/src/actions/mod.rs

@@ -14,6 +14,10 @@ pub mod move_clip_instances;
 pub mod reorder_clip_instances;
 pub mod paint_bucket;
 pub mod remove_effect;
+pub mod set_cycle_region;
+pub mod append_takes;
+pub mod manage_takes;
+pub mod set_active_take;
 pub mod set_document_properties;
 pub mod set_instance_properties;
 pub mod set_layer_properties;
@@ -50,6 +54,10 @@ pub mod set_text_content;
 pub mod resize_text_box;
 
 pub use add_clip_instance::AddClipInstanceAction;
+pub use set_cycle_region::SetCycleRegionAction;
+pub use append_takes::AppendTakesAction;
+pub use manage_takes::{DeleteTakeAction, DeleteUnusedTakesAction, RenameTakeAction};
+pub use set_active_take::SetActiveTakeAction;
 pub use add_effect::AddEffectAction;
 pub use add_layer::AddLayerAction;
 pub use add_shape::AddShapeAction;

lightningbeam-ui/lightningbeam-core/src/actions/move_clip_instances.rs

@@ -105,7 +105,7 @@ impl Action for MoveClipInstancesAction {
 
             let group: Vec<(Uuid, Beats, Beats)> = moves.iter().filter_map(|(id, old_start, _)| {
                 let inst = clip_instances.iter().find(|ci| &ci.id == id)?;
-                let dur = document.get_clip_duration(&inst.clip_id)?;
+                let dur = document.clip_trim_duration(&inst.clip_id)?;
                 let eff = inst.effective_duration_beats(dur, document.tempo_map());
                 Some((*id, *old_start, eff))
             }).collect();
@@ -190,7 +190,7 @@ impl Action for MoveClipInstancesAction {
 
     fn execute_backend(&mut self, backend: &mut crate::action::BackendContext, document: &Document) -> Result<(), String> {
         use crate::layer::AnyLayer;
-        use crate::clip::AudioClipType;
+        use crate::clip::ResolvedContent;
 
         // Get audio controller
         let controller = match backend.audio_controller.as_mut() {
@@ -211,8 +211,9 @@ impl Action for MoveClipInstancesAction {
                         // Check if this clip has a metatrack
                         if let Some(&metatrack_id) = backend.layer_to_track_map.get(&instance.clip_id) {
                             controller.set_offset(metatrack_id, document.tempo_map().beats_to_seconds(*new_start));
-                            controller.set_trim_start(metatrack_id, daw_backend::Seconds(instance.trim_start));
+                            // A vector clip's content is wall-clock, so its content times ARE seconds.
-                            controller.set_trim_end(metatrack_id, instance.trim_end.map(daw_backend::Seconds));
+                            controller.set_trim_start(metatrack_id, daw_backend::Seconds(instance.trim_start.raw()));
+                            controller.set_trim_end(metatrack_id, instance.trim_end.map(|t| daw_backend::Seconds(t.raw())));
                         }
                     }
                 }
@@ -246,12 +247,12 @@ impl Action for MoveClipInstancesAction {
                     .ok_or_else(|| format!("Audio clip {} not found", instance.clip_id))?;
 
                 // Handle move based on clip type
-                match &clip.clip_type {
+                match &instance.resolve(clip) {
-                    AudioClipType::Midi { midi_clip_id } => {
+                    ResolvedContent::Midi { midi_clip_id } => {
                         // For MIDI: move_clip expects the pool clip ID
                         controller.move_clip(*track_id, *midi_clip_id, *new_start);
                     }
-                    AudioClipType::Sampled { .. } => {
+                    ResolvedContent::Audio { .. } => {
                         // For sampled audio: move_clip expects the instance ID
                         let backend_instance_id = backend.clip_instance_to_backend_map.get(instance_id)
                             .ok_or_else(|| format!("Clip instance {} not mapped to backend", instance_id))?;
@@ -263,7 +264,7 @@ impl Action for MoveClipInstancesAction {
                             _ => return Err("Expected audio instance ID for sampled clip".to_string()),
                         }
                     }
-                    AudioClipType::Recording => {
+                    ResolvedContent::Recording => {
                         // Recording clips cannot be moved - skip
                     }
                 }
@@ -275,7 +276,7 @@ impl Action for MoveClipInstancesAction {
 
     fn rollback_backend(&mut self, backend: &mut crate::action::BackendContext, document: &Document) -> Result<(), String> {
         use crate::layer::AnyLayer;
-        use crate::clip::AudioClipType;
+        use crate::clip::ResolvedContent;
 
         // Get audio controller
         let controller = match backend.audio_controller.as_mut() {
@@ -295,8 +296,9 @@ impl Action for MoveClipInstancesAction {
                     if let Some(instance) = vl.clip_instances.iter().find(|ci| ci.id == *instance_id) {
                         if let Some(&metatrack_id) = backend.layer_to_track_map.get(&instance.clip_id) {
                             controller.set_offset(metatrack_id, document.tempo_map().beats_to_seconds(*old_start));
-                            controller.set_trim_start(metatrack_id, daw_backend::Seconds(instance.trim_start));
+                            // A vector clip's content is wall-clock, so its content times ARE seconds.
-                            controller.set_trim_end(metatrack_id, instance.trim_end.map(daw_backend::Seconds));
+                            controller.set_trim_start(metatrack_id, daw_backend::Seconds(instance.trim_start.raw()));
+                            controller.set_trim_end(metatrack_id, instance.trim_end.map(|t| daw_backend::Seconds(t.raw())));
                         }
                     }
                 }
@@ -330,12 +332,12 @@ impl Action for MoveClipInstancesAction {
                     .ok_or_else(|| format!("Audio clip {} not found", instance.clip_id))?;
 
                 // Handle move based on clip type (restore old position)
-                match &clip.clip_type {
+                match &instance.resolve(clip) {
-                    AudioClipType::Midi { midi_clip_id } => {
+                    ResolvedContent::Midi { midi_clip_id } => {
                         // For MIDI: move_clip expects the pool clip ID
                         controller.move_clip(*track_id, *midi_clip_id, *old_start);
                     }
-                    AudioClipType::Sampled { .. } => {
+                    ResolvedContent::Audio { .. } => {
                         // For sampled audio: move_clip expects the instance ID
                         let backend_instance_id = backend.clip_instance_to_backend_map.get(instance_id)
                             .ok_or_else(|| format!("Clip instance {} not mapped to backend", instance_id))?;
@@ -347,7 +349,7 @@ impl Action for MoveClipInstancesAction {
                             _ => return Err("Expected audio instance ID for sampled clip".to_string()),
                         }
                     }
-                    AudioClipType::Recording => {
+                    ResolvedContent::Recording => {
                         // Recording clips cannot be moved - skip
                     }
                 }

lightningbeam-ui/lightningbeam-core/src/actions/remove_clip_instances.rs

@@ -138,92 +138,23 @@ impl Action for RemoveClipInstancesAction {
         backend: &mut BackendContext,
         document: &Document,
     ) -> Result<(), String> {
-        use crate::clip::AudioClipType;
+        if backend.audio_controller.is_none() {
+            return Ok(());
+        }
 
-        let controller = match backend.audio_controller.as_mut() {
+        // Re-add the clips that were removed. `BackendContext::add_clip_instance` is the same
-            Some(c) => c,
+        // helper the add and split actions use, so the trim/duration conversions (and take-folder
-            None => return Ok(()),
+        // resolution) stay in exactly one place instead of being copied into every action that has
-        };
+        // to put a clip back.
-
+        let saved = std::mem::take(&mut self.saved);
-        // Re-add clips that were removed from backend
+        for (layer_id, instance) in &saved {
-        for (layer_id, instance) in &self.saved {
+            if !matches!(document.get_layer(layer_id), Some(AnyLayer::Audio(_))) {
-            let layer = match document.get_layer(layer_id) {
-                Some(l) => l,
-                None => continue,
-            };
-            if !matches!(layer, AnyLayer::Audio(_)) {
                 continue;
             }
-
+            // A missing track/clip just means there's nothing to restore on the backend.
-            let track_id = match backend.layer_to_track_map.get(layer_id) {
+            let _ = backend.add_clip_instance(document, layer_id, instance);
-                Some(id) => *id,
-                None => continue,
-            };
-
-            let clip = match document.get_audio_clip(&instance.clip_id) {
-                Some(c) => c,
-                None => continue,
-            };
-
-            match &clip.clip_type {
-                AudioClipType::Midi { midi_clip_id } => {
-                    use daw_backend::command::{Query, QueryResponse};
-
-                    let internal_start = instance.trim_start;
-                    let internal_end = instance.trim_end.unwrap_or(clip.content_duration().native());
-                    let external_start = instance.timeline_start;
-                    // MIDI trims are beats-domain, so the fallback span is beats too.
-                    let external_duration = instance
-                        .timeline_duration
-                        .unwrap_or(daw_backend::Beats(internal_end - internal_start));
-
-                    let midi_instance = daw_backend::MidiClipInstance::new(
-                        0,
-                        *midi_clip_id,
-                        daw_backend::Beats(internal_start),
-                        daw_backend::Beats(internal_end),
-                        external_start,
-                        external_duration,
-                    );
-
-                    let query = Query::AddMidiClipInstanceSync(track_id, midi_instance);
-                    if let Ok(QueryResponse::MidiClipInstanceAdded(Ok(new_id))) =
-                        controller.send_query(query)
-                    {
-                        backend.clip_instance_to_backend_map.insert(
-                            instance.id,
-                            BackendClipInstanceId::Midi(new_id),
-                        );
-                    }
-                }
-                AudioClipType::Sampled { audio_pool_index } => {
-                    let internal_start = instance.trim_start;
-                    let internal_end = instance.trim_end.unwrap_or(clip.content_duration().native());
-                    let start_time = instance.timeline_start;
-                    // Fallback span is the content seconds converted to beats at the
-                    // clip's start (not the seconds span treated as beats).
-                    let effective_duration = instance.timeline_duration.unwrap_or_else(|| {
-                        let tempo_map = document.tempo_map();
-                        let content_secs = daw_backend::Seconds(internal_end - internal_start);
-                        tempo_map.seconds_to_beats(tempo_map.beats_to_seconds(start_time) + content_secs)
-                            - start_time
-                    });
-
-                    let new_id = controller.add_audio_clip(
-                        track_id,
-                        *audio_pool_index,
-                        start_time,
-                        effective_duration,
-                        daw_backend::Seconds(internal_start),
-                    );
-                    backend.clip_instance_to_backend_map.insert(
-                        instance.id,
-                        BackendClipInstanceId::Audio(new_id),
-                    );
-                }
-                AudioClipType::Recording => {}
-            }
         }
+        self.saved = saved;
 
         // Clear saved backend IDs
         self.saved_backend_ids.clear();

lightningbeam-ui/lightningbeam-core/src/actions/set_active_take.rs

@@ -0,0 +1,117 @@
+//! Choose which take of a take-folder clip an instance plays.
+//!
+//! The take list lives on the *clip* but the selection lives on the *instance*, so two instances of
+//! the same folder can play different takes. Splitting a take-folder instance clones it, which is
+//! what makes comping work: set take 1 on the left half and take 3 on the right, and you've comped.
+//!
+//! There's no in-place pool-swap command in the backend, so switching a take means removing the
+//! instance's backend clip and re-adding it against the new take's audio/MIDI resource. Both halves
+//! of that go through `BackendContext`, which is also what `AddClipInstanceAction` uses.
+
+use crate::action::{Action, BackendClipInstanceId, BackendContext};
+use crate::document::Document;
+use crate::layer::AnyLayer;
+use uuid::Uuid;
+
+/// Action that points a clip instance at a different take of its take folder.
+#[derive(Clone)]
+pub struct SetActiveTakeAction {
+    layer_id: Uuid,
+    instance_id: Uuid,
+    new_take: Option<usize>,
+    old_take: Option<usize>,
+    /// The backend track/clip the instance was on before we swapped, so rollback can undo it.
+    backend_track_id: Option<daw_backend::TrackId>,
+}
+
+impl SetActiveTakeAction {
+    pub fn new(layer_id: Uuid, instance_id: Uuid, new_take: usize, old_take: Option<usize>) -> Self {
+        Self {
+            layer_id,
+            instance_id,
+            new_take: Some(new_take),
+            old_take,
+            backend_track_id: None,
+        }
+    }
+
+    /// Point the instance at `take`, mutating the document. Shared by execute and rollback.
+    fn apply(&self, document: &mut Document, take: Option<usize>) -> Result<(), String> {
+        let layer = document
+            .get_layer_mut(&self.layer_id)
+            .ok_or_else(|| format!("Layer {} not found", self.layer_id))?;
+        let AnyLayer::Audio(audio_layer) = layer else {
+            return Err("Take folders only exist on audio layers".to_string());
+        };
+        let instance = audio_layer
+            .clip_instances
+            .iter_mut()
+            .find(|ci| ci.id == self.instance_id)
+            .ok_or_else(|| format!("Clip instance {} not found", self.instance_id))?;
+        instance.active_take = take;
+        Ok(())
+    }
+
+    /// Swap the instance's backend clip to whatever take the document now says is active.
+    ///
+    /// Called after the document has already been mutated, so re-adding just re-resolves the
+    /// instance — `BackendContext::add_clip_instance` reads `active_take` itself.
+    fn resync(&mut self, backend: &mut BackendContext, document: &Document) -> Result<(), String> {
+        let instance = document
+            .get_layer(&self.layer_id)
+            .and_then(|l| match l {
+                AnyLayer::Audio(al) => al.clip_instances.iter().find(|ci| ci.id == self.instance_id),
+                _ => None,
+            })
+            .cloned()
+            .ok_or_else(|| format!("Clip instance {} not found", self.instance_id))?;
+
+        // Drop the old backend clip first. Its track comes from the map we're about to overwrite,
+        // so read it before add_clip_instance replaces the entry.
+        let existing: Option<BackendClipInstanceId> = backend
+            .clip_instance_to_backend_map
+            .get(&self.instance_id)
+            .copied();
+        let track_id = backend.layer_to_track_map.get(&self.layer_id).copied();
+        if let (Some(backend_id), Some(track_id)) = (existing, track_id) {
+            backend.remove_clip_instance(track_id, backend_id, self.instance_id);
+        }
+
+        let added = backend.add_clip_instance(document, &self.layer_id, &instance)?;
+        self.backend_track_id = added.map(|(track_id, _)| track_id);
+        Ok(())
+    }
+}
+
+impl Action for SetActiveTakeAction {
+    fn execute(&mut self, document: &mut Document) -> Result<(), String> {
+        self.apply(document, self.new_take)
+    }
+
+    fn rollback(&mut self, document: &mut Document) -> Result<(), String> {
+        self.apply(document, self.old_take)
+    }
+
+    fn description(&self) -> String {
+        match self.new_take {
+            Some(i) => format!("Select take {}", i + 1),
+            None => "Select take".to_string(),
+        }
+    }
+
+    fn execute_backend(
+        &mut self,
+        backend: &mut BackendContext,
+        document: &Document,
+    ) -> Result<(), String> {
+        self.resync(backend, document)
+    }
+
+    fn rollback_backend(
+        &mut self,
+        backend: &mut BackendContext,
+        document: &Document,
+    ) -> Result<(), String> {
+        self.resync(backend, document)
+    }
+}

lightningbeam-ui/lightningbeam-core/src/actions/set_cycle_region.rs

@@ -0,0 +1,93 @@
+//! Set the transport cycle (loop) region.
+//!
+//! The cycle region is document state (it's saved in the `.beam`), so changing it goes through the
+//! action system like any other edit: it's undoable and it marks the document modified.
+//!
+//! The region is stored in **beats** so it stays put musically across tempo changes. Callers commit
+//! one action per gesture (e.g. on drag release, or a toggle click) rather than one per frame —
+//! the timeline previews the drag from its own local state, exactly like a clip drag does.
+
+use crate::action::{Action, BackendContext};
+use crate::document::Document;
+use daw_backend::Beats;
+
+/// Action that sets the cycle region and/or whether the transport loops over it.
+#[derive(Clone)]
+pub struct SetCycleRegionAction {
+    old_region: Option<(Beats, Beats)>,
+    old_enabled: bool,
+    new_region: Option<(Beats, Beats)>,
+    new_enabled: bool,
+}
+
+impl SetCycleRegionAction {
+    /// Build from the document's current state and the desired new region/enabled flag.
+    pub fn new(
+        document: &Document,
+        new_region: Option<(Beats, Beats)>,
+        new_enabled: bool,
+    ) -> Self {
+        Self {
+            old_region: document.cycle_region,
+            old_enabled: document.cycle_enabled,
+            new_region,
+            new_enabled,
+        }
+    }
+
+    /// Toggle looping on/off, leaving the region itself alone.
+    pub fn toggle_enabled(document: &Document) -> Self {
+        Self::new(document, document.cycle_region, !document.cycle_enabled)
+    }
+
+    /// True if this action would not actually change anything (lets callers skip a no-op undo entry).
+    pub fn is_noop(&self) -> bool {
+        self.old_region == self.new_region && self.old_enabled == self.new_enabled
+    }
+}
+
+impl Action for SetCycleRegionAction {
+    fn execute(&mut self, document: &mut Document) -> Result<(), String> {
+        document.cycle_region = self.new_region;
+        document.cycle_enabled = self.new_enabled;
+        Ok(())
+    }
+
+    fn rollback(&mut self, document: &mut Document) -> Result<(), String> {
+        document.cycle_region = self.old_region;
+        document.cycle_enabled = self.old_enabled;
+        Ok(())
+    }
+
+    fn description(&self) -> String {
+        "Set cycle region".to_string()
+    }
+
+    fn execute_backend(
+        &mut self,
+        backend: &mut BackendContext,
+        _document: &Document,
+    ) -> Result<(), String> {
+        let controller = match backend.audio_controller.as_mut() {
+            Some(c) => c,
+            None => return Ok(()),
+        };
+        controller.set_loop_region(self.new_region);
+        controller.set_loop_enabled(self.new_enabled);
+        Ok(())
+    }
+
+    fn rollback_backend(
+        &mut self,
+        backend: &mut BackendContext,
+        _document: &Document,
+    ) -> Result<(), String> {
+        let controller = match backend.audio_controller.as_mut() {
+            Some(c) => c,
+            None => return Ok(()),
+        };
+        controller.set_loop_region(self.old_region);
+        controller.set_loop_enabled(self.old_enabled);
+        Ok(())
+    }
+}

lightningbeam-ui/lightningbeam-core/src/actions/split_clip_instance.rs

@@ -7,6 +7,7 @@ use crate::action::{Action, BackendContext};
 use crate::clip::ClipInstance;
 use crate::document::Document;
 use crate::layer::AnyLayer;
+use daw_backend::ContentTime;
 use uuid::Uuid;
 
 /// Action that splits a clip instance at a specific timeline position
@@ -25,7 +26,7 @@ pub struct SplitClipInstanceAction {
 
     // Stored during execute for rollback
     /// Original trim_end value of the left (original) instance
-    original_trim_end: Option<f64>,
+    original_trim_end: Option<ContentTime>,
     /// Original timeline_duration value of the left (original) instance (beats)
     original_timeline_duration: Option<daw_backend::Beats>,
     /// ID of the new (right) instance created by the split
@@ -122,13 +123,15 @@ impl Action for SplitClipInstanceAction {
             .find(|ci| ci.id == self.instance_id)
             .ok_or_else(|| format!("Clip instance {} not found", self.instance_id))?;
 
-        // Get the clip's duration
+        // The clip's content duration in its OWN domain — seconds for audio/video/vector, beats for
-        let clip_duration = document
+        // MIDI. All the content math below is trim-domain, so it has to be done in whichever domain
-            .get_clip_duration(&instance.clip_id)
+        // this clip uses; a seconds duration would silently be added to a MIDI clip's beats trim.
+        let trim_duration = document
+            .clip_trim_duration(&instance.clip_id)
             .ok_or_else(|| format!("Clip {} not found", instance.clip_id))?;
 
         // Calculate the effective duration and timeline end (both in beats)
-        let effective_duration = instance.effective_duration(clip_duration, document.tempo_map());
+        let effective_duration = instance.effective_duration(trim_duration, document.tempo_map());
         let timeline_end = instance.timeline_start + effective_duration;
 
         // Validate: split_time must be strictly within the clip's timeline span
@@ -146,27 +149,30 @@ impl Action for SplitClipInstanceAction {
         self.original_trim_end = instance.trim_end;
         self.original_timeline_duration = instance.timeline_duration;
 
-        // Check if this is a looping clip. `content_duration` is a trim-domain
-        // span (seconds), so `clip_duration` must be unwrapped as seconds.
         let is_looping = instance.timeline_duration.is_some();
-        let content_duration = instance.trim_end.unwrap_or(clip_duration.seconds_to_f64()) - instance.trim_start;
+        let content_duration = ContentTime(instance.content_window(trim_duration).native());
 
         // Timeline split point (beats).
         let time_into_clip = self.split_time - instance.timeline_start;
         let left_duration = time_into_clip;
         let right_duration = effective_duration - left_duration;
 
-        // How far the split lands into the clip's *content* (seconds, trim domain).
+        // How far the split lands into the clip's *content*, expressed in the content domain: beats
+        // content takes the beats delta directly, wall-clock content takes the seconds delta.
         let tempo_map = document.tempo_map();
-        let time_into_clip_secs = (tempo_map.beats_to_seconds(self.split_time)
+        let time_into_content = ContentTime(match trim_duration {
-            - tempo_map.beats_to_seconds(instance.timeline_start)).seconds_to_f64();
+            crate::clip::ClipDuration::Beats(_) => time_into_clip.beats_to_f64(),
+            crate::clip::ClipDuration::Seconds(_) => (tempo_map.beats_to_seconds(self.split_time)
+                - tempo_map.beats_to_seconds(instance.timeline_start))
+            .seconds_to_f64(),
+        });
 
-        // Calculate content split time (seconds)
+        // Calculate the content split point (content domain).
-        let content_split_time = if is_looping {
+        let content_split_time = if is_looping && content_duration > ContentTime::ZERO {
             // For looping clips, wrap around content
-            instance.trim_start + (time_into_clip_secs % content_duration)
+            instance.trim_start + (time_into_content % content_duration)
         } else {
-            instance.trim_start + time_into_clip_secs
+            instance.trim_start + time_into_content
         };
 
         // Clone the instance for the right side
@@ -357,119 +363,63 @@ impl Action for SplitClipInstanceAction {
             .get_audio_clip(&new_instance.clip_id)
             .ok_or_else(|| "Audio clip not found".to_string())?;
 
-        // Look up backend track ID from layer mapping
+        use crate::clip::ResolvedContent;
-        let backend_track_id = backend
+        if matches!(original_instance.resolve(clip), ResolvedContent::Recording) {
+            return Err("Cannot split a clip that is currently recording".to_string());
+        }
+
+        // A split is: shorten the left half's backend clip, then add the right half as a new one.
+        //
+        // 1. Trim the left (original) instance. `trim_range` tags the bounds with the clip's own
+        //    content domain, so a MIDI clip's beats trims can't be sent as seconds.
+        let left_trim = clip.trim_range(
+            original_instance.trim_start,
+            original_instance
+                .trim_end
+                .unwrap_or(ContentTime(clip.content_duration().native())),
+        );
+        let new_instance = new_instance.clone();
+
+        let backend_track_id = *backend
             .layer_to_track_map
             .get(&self.layer_id)
             .ok_or_else(|| format!("Layer {} not mapped to backend track", self.layer_id))?;
+        let left_backend_id = backend
+            .clip_instance_to_backend_map
+            .get(&self.instance_id)
+            .copied();
 
-        // Get audio controller
+        {
-        let controller = backend
+            let controller = backend
-            .audio_controller
+                .audio_controller
-            .as_mut()
+                .as_mut()
-            .ok_or_else(|| "Audio controller not available".to_string())?;
+                .ok_or_else(|| "Audio controller not available".to_string())?;
-
+            match left_backend_id {
-        // Handle different clip types
+                Some(crate::action::BackendClipInstanceId::Midi(id))
-        use crate::clip::AudioClipType;
+                | Some(crate::action::BackendClipInstanceId::Audio(id)) => {
-        match &clip.clip_type {
+                    controller.trim_clip(backend_track_id, id, left_trim);
-            AudioClipType::Midi { midi_clip_id } => {
-                use daw_backend::command::{Query, QueryResponse};
-
-                // 1. Trim the original (left) instance
-                let orig_internal_start = original_instance.trim_start;
-                let orig_internal_end = original_instance.trim_end.unwrap_or(clip.content_duration().native());
-
-                // Look up the original backend instance ID
-                if let Some(crate::action::BackendClipInstanceId::Midi(orig_backend_id)) =
-                    backend.clip_instance_to_backend_map.get(&self.instance_id)
-                {
-                    controller.trim_clip(*backend_track_id, *orig_backend_id, orig_internal_start, orig_internal_end);
                 }
-
+                None => {}
-                // 2. Add the new (right) instance
-                let internal_start = new_instance.trim_start;
-                let internal_end = new_instance.trim_end.unwrap_or(clip.content_duration().native());
-                let external_start = new_instance.timeline_start;
-                // MIDI trims are beats-domain, so the fallback span is beats too.
-                let external_duration = new_instance
-                    .timeline_duration
-                    .unwrap_or(daw_backend::Beats(internal_end - internal_start));
-
-                let instance = daw_backend::MidiClipInstance::new(
-                    0,
-                    *midi_clip_id,
-                    daw_backend::Beats(internal_start),
-                    daw_backend::Beats(internal_end),
-                    external_start,
-                    external_duration,
-                );
-
-                let query = Query::AddMidiClipInstanceSync(*backend_track_id, instance);
-
-                match controller.send_query(query)? {
-                    QueryResponse::MidiClipInstanceAdded(Ok(instance_id)) => {
-                        self.backend_track_id = Some(*backend_track_id);
-                        self.backend_midi_instance_id = Some(instance_id);
-
-                        backend.clip_instance_to_backend_map.insert(
-                            new_instance_id,
-                            crate::action::BackendClipInstanceId::Midi(instance_id),
-                        );
-
-                        Ok(())
-                    }
-                    QueryResponse::MidiClipInstanceAdded(Err(e)) => Err(e),
-                    _ => Err("Unexpected query response".to_string()),
-                }
-            }
-            AudioClipType::Sampled { audio_pool_index } => {
-                // 1. Trim the original (left) instance
-                let orig_internal_start = original_instance.trim_start;
-                let orig_internal_end = original_instance.trim_end.unwrap_or(clip.content_duration().native());
-
-                // Look up the original backend instance ID
-                if let Some(crate::action::BackendClipInstanceId::Audio(orig_backend_id)) =
-                    backend.clip_instance_to_backend_map.get(&self.instance_id)
-                {
-                    controller.trim_clip(*backend_track_id, *orig_backend_id, orig_internal_start, orig_internal_end);
-                }
-
-                // 2. Add the new (right) instance
-                let internal_start = new_instance.trim_start;
-                let internal_end = new_instance.trim_end.unwrap_or(clip.content_duration().native());
-                let start_time = new_instance.timeline_start;
-                // Fallback span is the content seconds converted to beats at the
-                // clip's start (not the seconds span treated as beats).
-                let effective_duration = new_instance.timeline_duration.unwrap_or_else(|| {
-                    let tempo_map = document.tempo_map();
-                    let content_secs = daw_backend::Seconds(internal_end - internal_start);
-                    tempo_map.seconds_to_beats(tempo_map.beats_to_seconds(start_time) + content_secs)
-                        - start_time
-                });
-
-                let instance_id = controller.add_audio_clip(
-                    *backend_track_id,
-                    *audio_pool_index,
-                    start_time,
-                    effective_duration,
-                    daw_backend::Seconds(internal_start),
-                );
-
-                self.backend_track_id = Some(*backend_track_id);
-                self.backend_audio_instance_id = Some(instance_id);
-
-                backend.clip_instance_to_backend_map.insert(
-                    new_instance_id,
-                    crate::action::BackendClipInstanceId::Audio(instance_id),
-                );
-
-                Ok(())
-            }
-            AudioClipType::Recording => {
-                // Recording clips cannot be split
-                Err("Cannot split a clip that is currently recording".to_string())
             }
         }
+
+        // 2. Add the right (new) instance via the shared helper — same one AddClipInstanceAction
+        //    uses, so the trim/duration conversions live in exactly one place.
+        if let Some((track_id, backend_id)) =
+            backend.add_clip_instance(document, &self.layer_id, &new_instance)?
+        {
+            self.backend_track_id = Some(track_id);
+            match backend_id {
+                crate::action::BackendClipInstanceId::Midi(id) => {
+                    self.backend_midi_instance_id = Some(id)
+                }
+                crate::action::BackendClipInstanceId::Audio(id) => {
+                    self.backend_audio_instance_id = Some(id)
+                }
+            }
+        }
+
+        Ok(())
     }
 
     fn rollback_backend(
@@ -499,26 +449,28 @@ impl Action for SplitClipInstanceAction {
                     if let Some(instance) = al.clip_instances.iter().find(|ci| ci.id == self.instance_id) {
                         if let Some(clip) = document.get_audio_clip(&instance.clip_id) {
                             let orig_internal_start = instance.trim_start;
-                            let orig_internal_end = self.original_trim_end.unwrap_or(clip.content_duration().native());
+                            let orig_internal_end = self
+                                .original_trim_end
+                                .unwrap_or(ContentTime(clip.content_duration().native()));
 
                             // Restore based on clip type
-                            use crate::clip::AudioClipType;
+                            use crate::clip::ResolvedContent;
-                            match &clip.clip_type {
+                            match &instance.resolve(clip) {
-                                AudioClipType::Midi { .. } => {
+                                ResolvedContent::Midi { .. } => {
                                     if let Some(crate::action::BackendClipInstanceId::Midi(orig_backend_id)) =
                                         backend.clip_instance_to_backend_map.get(&self.instance_id)
                                     {
-                                        controller.trim_clip(track_id, *orig_backend_id, orig_internal_start, orig_internal_end);
+                                        controller.trim_clip(track_id, *orig_backend_id, clip.trim_range(orig_internal_start, orig_internal_end));
                                     }
                                 }
-                                AudioClipType::Sampled { .. } => {
+                                ResolvedContent::Audio { .. } => {
                                     if let Some(crate::action::BackendClipInstanceId::Audio(orig_backend_id)) =
                                         backend.clip_instance_to_backend_map.get(&self.instance_id)
                                     {
-                                        controller.trim_clip(track_id, *orig_backend_id, orig_internal_start, orig_internal_end);
+                                        controller.trim_clip(track_id, *orig_backend_id, clip.trim_range(orig_internal_start, orig_internal_end));
                                     }
                                 }
-                                AudioClipType::Recording => {
+                                ResolvedContent::Recording => {
                                     // Recording clips - nothing to rollback
                                 }
                             }
@@ -554,8 +506,8 @@ mod tests {
         // Create a clip instance at timeline 0, with trim 0-10 (10 seconds)
         let mut clip_instance = ClipInstance::new(clip_id);
         clip_instance.timeline_start = daw_backend::Beats::ZERO;
-        clip_instance.trim_start = 0.0;
+        clip_instance.trim_start = ContentTime::ZERO;
-        clip_instance.trim_end = Some(10.0);
+        clip_instance.trim_end = Some(ContentTime(10.0));
         let instance_id = clip_instance.id;
         vector_layer.clip_instances.push(clip_instance);
 
@@ -575,4 +527,42 @@ mod tests {
         let action = SplitClipInstanceAction::new(Uuid::new_v4(), Uuid::new_v4(), daw_backend::Beats(5.0));
         assert_eq!(action.description(), "Split clip instance");
     }
+
+    #[test]
+    fn splitting_a_midi_clip_stays_in_the_beats_domain() {
+        // Regression: `trim_start`/`trim_end` are domain-polymorphic — SECONDS for audio/video/
+        // vector, but BEATS for MIDI (the backend takes MIDI trims as `Beats`). Split used to map
+        // the split point into the clip's content in seconds unconditionally, so on a MIDI clip it
+        // added a seconds delta to a beats offset. At anything but 60 BPM the right half started at
+        // the wrong place in the content.
+        //
+        // At 120 BPM, beat 4 is 2 SECONDS in. The right half must trim to beat 4, not "4 seconds"
+        // (= beat 8) and not 2 (the seconds value).
+        let mut document = Document::new("Test");
+        document.set_bpm(120.0);
+
+        // 8-beat MIDI clip at the timeline origin.
+        let clip = crate::clip::AudioClip::new_midi("Midi", 1, daw_backend::Beats(8.0));
+        let clip_id = document.add_audio_clip(clip);
+
+        let mut audio_layer = crate::layer::AudioLayer::new("Layer 1");
+        let mut instance = ClipInstance::new(clip_id);
+        instance.timeline_start = daw_backend::Beats::ZERO;
+        instance.trim_start = ContentTime::ZERO;
+        instance.trim_end = Some(ContentTime(8.0)); // beats
+        let instance_id = instance.id;
+        audio_layer.clip_instances.push(instance);
+        let layer_id = document.root.add_child(AnyLayer::Audio(audio_layer));
+
+        let mut action = SplitClipInstanceAction::new(layer_id, instance_id, daw_backend::Beats(4.0));
+        action.execute(&mut document).expect("split");
+        let new_id = action.new_instance_id().expect("right instance");
+
+        let AnyLayer::Audio(al) = document.get_layer(&layer_id).unwrap() else { panic!() };
+        let right = al.clip_instances.iter().find(|ci| ci.id == new_id).unwrap();
+        let left = al.clip_instances.iter().find(|ci| ci.id == instance_id).unwrap();
+
+        assert_eq!(right.trim_start, ContentTime(4.0), "right half must start 4 BEATS into the content");
+        assert_eq!(left.trim_end, Some(ContentTime(4.0)), "left half must end 4 BEATS into the content");
+    }
 }

lightningbeam-ui/lightningbeam-core/src/actions/trim_clip_instances.rs

@@ -6,7 +6,7 @@ use crate::action::Action;
 use crate::clip::ClipInstance;
 use crate::document::Document;
 use crate::layer::AnyLayer;
-use daw_backend::{Beats, Seconds};
+use daw_backend::{Beats, ContentTime, Seconds};
 use std::collections::HashMap;
 use uuid::Uuid;
 
@@ -32,15 +32,57 @@ pub struct TrimClipInstancesAction {
 pub struct TrimData {
     /// For TrimLeft: trim_start value
     /// For TrimRight: trim_end value (Option because it can be None)
-    pub trim_value: Option<f64>,
+    ///
+    /// A content time — measured in the clip's own domain (seconds for audio/video/vector, beats
+    /// for MIDI), so it must be resolved against the clip before meeting a timeline position.
+    pub trim_value: Option<ContentTime>,
     /// For TrimLeft: timeline_start value (where the clip appears on timeline, beats)
     /// For TrimRight: unused (None)
     pub timeline_start: Option<Beats>,
 }
 
+/// A wall-clock gap on the timeline, expressed in a clip's content domain.
+///
+/// Trim validation clamps how far a clip may be dragged against the empty space next to it, and that
+/// space is measured on the timeline (seconds) while the trim lives in the clip's content domain. For
+/// wall-clock content they're the same number; for MIDI (beats content) the gap has to be converted
+/// at the clip's position, or a seconds gap silently clamps a beats trim.
+fn gap_to_content(
+    gap: Seconds,
+    clip_content: crate::clip::ClipDuration,
+    timeline_start: Beats,
+    tempo_map: &crate::tempo_map::TempoMap,
+) -> ContentTime {
+    match clip_content {
+        crate::clip::ClipDuration::Seconds(_) => ContentTime(gap.seconds_to_f64()),
+        crate::clip::ClipDuration::Beats(_) => {
+            let beats = tempo_map
+                .seconds_to_beats(tempo_map.beats_to_seconds(timeline_start) + gap)
+                - timeline_start;
+            ContentTime(beats.beats_to_f64())
+        }
+    }
+}
+
+/// The inverse: a content-domain span as wall-clock seconds at the clip's position.
+fn content_to_secs(
+    span: ContentTime,
+    clip_content: crate::clip::ClipDuration,
+    timeline_start: Beats,
+    tempo_map: &crate::tempo_map::TempoMap,
+) -> Seconds {
+    match clip_content {
+        crate::clip::ClipDuration::Seconds(_) => Seconds(span.raw()),
+        crate::clip::ClipDuration::Beats(_) => {
+            tempo_map.beats_to_seconds(timeline_start + Beats(span.raw()))
+                - tempo_map.beats_to_seconds(timeline_start)
+        }
+    }
+}
+
 impl TrimData {
     /// Create TrimData for left trim
-    pub fn left(trim_start: f64, timeline_start: Beats) -> Self {
+    pub fn left(trim_start: ContentTime, timeline_start: Beats) -> Self {
         Self {
             trim_value: Some(trim_start),
             timeline_start: Some(timeline_start),
@@ -48,7 +90,7 @@ impl TrimData {
     }
 
     /// Create TrimData for right trim
-    pub fn right(trim_end: Option<f64>) -> Self {
+    pub fn right(trim_end: Option<ContentTime>) -> Self {
         Self {
             trim_value: trim_end,
             timeline_start: None,
@@ -192,7 +234,8 @@ impl Action for TrimClipInstancesAction {
                     .find(|ci| &ci.id == instance_id)
                     .ok_or_else(|| format!("Instance {} not found", instance_id))?;
 
-                let clip_duration = document.get_clip_duration(&instance.clip_id)
+                // The clip's content duration in ITS OWN domain, so trims resolve correctly for MIDI.
+                let clip_content = document.clip_trim_duration(&instance.clip_id)
                     .ok_or_else(|| format!("Clip {} not found", instance.clip_id))?;
 
                 let mut clamped_new = new.clone();
@@ -204,23 +247,34 @@ impl Action for TrimClipInstancesAction {
                         {
                             // If extending to the left (new_trim < old_trim)
                             if should_validate && new_trim < old_trim {
-                                // Max leftward extension as content seconds (the gap's wall-clock span).
-                                let max_extend_secs = document.find_max_trim_extend_left(
-                                    layer_id,
-                                    instance_id,
-                                    instance.timeline_start,
-                                ).seconds_to_f64();
-
-                                // Calculate how much we want to extend (content seconds)
-                                let desired_extend = old_trim - new_trim;
-
-                                // Clamp to max allowed
-                                let actual_extend = desired_extend.min(max_extend_secs);
-                                let clamped_trim_start = old_trim - actual_extend;
-                                // Move the timeline left by the same wall-clock seconds.
                                 let tempo_map = document.tempo_map();
+
+                                // Max leftward extension: the gap's wall-clock span, converted into
+                                // the clip's content domain so it can clamp a content-domain trim.
+                                let max_extend = gap_to_content(
+                                    document.find_max_trim_extend_left(
+                                        layer_id,
+                                        instance_id,
+                                        instance.timeline_start,
+                                    ),
+                                    clip_content,
+                                    instance.timeline_start,
+                                    tempo_map,
+                                );
+
+                                let desired_extend = old_trim - new_trim;
+                                let actual_extend = desired_extend.min(max_extend);
+                                let clamped_trim_start = old_trim - actual_extend;
+
+                                // Move the timeline left by the same span, as wall-clock seconds.
+                                let shift = content_to_secs(
+                                    actual_extend,
+                                    clip_content,
+                                    instance.timeline_start,
+                                    tempo_map,
+                                );
                                 let clamped_timeline_start = tempo_map
-                                    .seconds_to_beats(tempo_map.beats_to_seconds(old_timeline) - Seconds(actual_extend))
+                                    .seconds_to_beats(tempo_map.beats_to_seconds(old_timeline) - shift)
                                     .max(Beats::ZERO);
 
                                 clamped_new = TrimData::left(clamped_trim_start, clamped_timeline_start);
@@ -228,36 +282,39 @@ impl Action for TrimClipInstancesAction {
                         }
                     }
                     TrimType::TrimRight => {
-                        let old_trim_end = old.trim_value.unwrap_or(clip_duration.seconds_to_f64());
+                        let content_end = ContentTime(clip_content.native());
-                        let new_trim_end = new.trim_value.unwrap_or(clip_duration.seconds_to_f64());
+                        let old_trim_end = old.trim_value.unwrap_or(content_end);
+                        let new_trim_end = new.trim_value.unwrap_or(content_end);
 
                         // If extending to the right (new_trim_end > old_trim_end)
                         if should_validate && new_trim_end > old_trim_end {
                             let tempo_map = document.tempo_map();
-                            // Current effective duration in beats (content seconds
-                            // converted to beats at the clip's start).
-                            let content_secs = Seconds(old_trim_end - instance.trim_start);
-                            let current_effective_duration = tempo_map.seconds_to_beats(
-                                tempo_map.beats_to_seconds(instance.timeline_start) + content_secs,
-                            ) - instance.timeline_start;
 
-                            // Max rightward extension as content seconds (the gap's wall-clock span).
+                            // How long the clip currently occupies the timeline, in beats. Resolved
-                            let max_extend_secs = document.find_max_trim_extend_right(
+                            // in the clip's own domain, so a MIDI clip's beats content isn't run
-                                layer_id,
+                            // through the seconds→beats conversion a second time.
-                                instance_id,
+                            let current_effective_duration = instance
+                                .effective_duration_beats(clip_content, tempo_map);
+
+                            // Max rightward extension: the gap's wall-clock span, in content domain.
+                            let max_extend = gap_to_content(
+                                document.find_max_trim_extend_right(
+                                    layer_id,
+                                    instance_id,
+                                    instance.timeline_start,
+                                    current_effective_duration,
+                                ),
+                                clip_content,
                                 instance.timeline_start,
-                                current_effective_duration,
+                                tempo_map,
-                            ).seconds_to_f64();
+                            );
 
-                            // Calculate how much we want to extend (content seconds)
                             let desired_extend = new_trim_end - old_trim_end;
-
+                            let actual_extend = desired_extend.min(max_extend);
-                            // Clamp to max allowed
-                            let actual_extend = desired_extend.min(max_extend_secs);
                             let clamped_trim_end = old_trim_end + actual_extend;
 
-                            // Don't exceed clip duration
+                            // Don't exceed the clip's content.
-                            let final_trim_end = clamped_trim_end.min(clip_duration.seconds_to_f64());
+                            let final_trim_end = clamped_trim_end.min(content_end);
 
                             clamped_new = TrimData::right(Some(final_trim_end));
                         }
@@ -366,7 +423,7 @@ impl Action for TrimClipInstancesAction {
 
     fn execute_backend(&mut self, backend: &mut crate::action::BackendContext, document: &Document) -> Result<(), String> {
         use crate::layer::AnyLayer;
-        use crate::clip::AudioClipType;
+        use crate::clip::ResolvedContent;
 
         // Get audio controller
         let controller = match backend.audio_controller.as_mut() {
@@ -387,8 +444,9 @@ impl Action for TrimClipInstancesAction {
                         if let Some(&metatrack_id) = backend.layer_to_track_map.get(&instance.clip_id) {
                             // Instance already has new values after execute()
                             controller.set_offset(metatrack_id, document.tempo_map().beats_to_seconds(instance.timeline_start));
-                            controller.set_trim_start(metatrack_id, daw_backend::Seconds(instance.trim_start));
+                            // A vector clip's content is wall-clock, so its content times ARE seconds.
-                            controller.set_trim_end(metatrack_id, instance.trim_end.map(daw_backend::Seconds));
+                            controller.set_trim_start(metatrack_id, daw_backend::Seconds(instance.trim_start.raw()));
+                            controller.set_trim_end(metatrack_id, instance.trim_end.map(|t| daw_backend::Seconds(t.raw())));
                         }
                     }
                 }
@@ -424,27 +482,29 @@ impl Action for TrimClipInstancesAction {
                 // Calculate new internal_start and internal_end for backend
                 // Note: instance already has the new trim values after execute()
                 let internal_start = instance.trim_start;
-                let internal_end = instance.trim_end.unwrap_or(clip.content_duration().native());
+                let internal_end = instance
+                    .trim_end
+                    .unwrap_or(ContentTime(clip.content_duration().native()));
 
                 // Handle trim based on clip type
-                match &clip.clip_type {
+                match &instance.resolve(clip) {
-                    AudioClipType::Midi { midi_clip_id } => {
+                    ResolvedContent::Midi { midi_clip_id } => {
                         // For MIDI: trim_clip expects the pool clip ID
-                        controller.trim_clip(*track_id, *midi_clip_id, internal_start, internal_end);
+                        controller.trim_clip(*track_id, *midi_clip_id, clip.trim_range(internal_start, internal_end));
                     }
-                    AudioClipType::Sampled { .. } => {
+                    ResolvedContent::Audio { .. } => {
                         // For sampled audio: trim_clip expects the instance ID
                         let backend_instance_id = backend.clip_instance_to_backend_map.get(instance_id)
                             .ok_or_else(|| format!("Clip instance {} not mapped to backend", instance_id))?;
 
                         match backend_instance_id {
                             crate::action::BackendClipInstanceId::Audio(audio_id) => {
-                                controller.trim_clip(*track_id, *audio_id, internal_start, internal_end);
+                                controller.trim_clip(*track_id, *audio_id, clip.trim_range(internal_start, internal_end));
                             }
                             _ => return Err("Expected audio instance ID for sampled clip".to_string()),
                         }
                     }
-                    AudioClipType::Recording => {
+                    ResolvedContent::Recording => {
                         // Recording clips cannot be trimmed - skip
                     }
                 }
@@ -456,7 +516,7 @@ impl Action for TrimClipInstancesAction {
 
     fn rollback_backend(&mut self, backend: &mut crate::action::BackendContext, document: &Document) -> Result<(), String> {
         use crate::layer::AnyLayer;
-        use crate::clip::AudioClipType;
+        use crate::clip::ResolvedContent;
 
         // Get audio controller
         let controller = match backend.audio_controller.as_mut() {
@@ -477,8 +537,9 @@ impl Action for TrimClipInstancesAction {
                         if let Some(&metatrack_id) = backend.layer_to_track_map.get(&instance.clip_id) {
                             // Instance already has old values after rollback()
                             controller.set_offset(metatrack_id, document.tempo_map().beats_to_seconds(instance.timeline_start));
-                            controller.set_trim_start(metatrack_id, daw_backend::Seconds(instance.trim_start));
+                            // A vector clip's content is wall-clock, so its content times ARE seconds.
-                            controller.set_trim_end(metatrack_id, instance.trim_end.map(daw_backend::Seconds));
+                            controller.set_trim_start(metatrack_id, daw_backend::Seconds(instance.trim_start.raw()));
+                            controller.set_trim_end(metatrack_id, instance.trim_end.map(|t| daw_backend::Seconds(t.raw())));
                         }
                     }
                 }
@@ -512,34 +573,35 @@ impl Action for TrimClipInstancesAction {
                     .ok_or_else(|| format!("Audio clip {} not found", instance.clip_id))?;
 
                 // Calculate old internal_start and internal_end for backend
+                let content_end = ContentTime(clip.content_duration().native());
                 let internal_start = match trim_type {
-                    TrimType::TrimLeft => old.trim_value.unwrap_or(0.0),
+                    TrimType::TrimLeft => old.trim_value.unwrap_or(ContentTime::ZERO),
                     TrimType::TrimRight => instance.trim_start, // trim_start wasn't changed
                 };
                 let internal_end = match trim_type {
-                    TrimType::TrimLeft => instance.trim_end.unwrap_or(clip.content_duration().native()), // trim_end wasn't changed
+                    TrimType::TrimLeft => instance.trim_end.unwrap_or(content_end), // trim_end wasn't changed
-                    TrimType::TrimRight => old.trim_value.unwrap_or(clip.content_duration().native()),
+                    TrimType::TrimRight => old.trim_value.unwrap_or(content_end),
                 };
 
                 // Handle trim based on clip type
-                match &clip.clip_type {
+                match &instance.resolve(clip) {
-                    AudioClipType::Midi { midi_clip_id } => {
+                    ResolvedContent::Midi { midi_clip_id } => {
                         // For MIDI: trim_clip expects the pool clip ID
-                        controller.trim_clip(*track_id, *midi_clip_id, internal_start, internal_end);
+                        controller.trim_clip(*track_id, *midi_clip_id, clip.trim_range(internal_start, internal_end));
                     }
-                    AudioClipType::Sampled { .. } => {
+                    ResolvedContent::Audio { .. } => {
                         // For sampled audio: trim_clip expects the instance ID
                         let backend_instance_id = backend.clip_instance_to_backend_map.get(instance_id)
                             .ok_or_else(|| format!("Clip instance {} not mapped to backend", instance_id))?;
 
                         match backend_instance_id {
                             crate::action::BackendClipInstanceId::Audio(audio_id) => {
-                                controller.trim_clip(*track_id, *audio_id, internal_start, internal_end);
+                                controller.trim_clip(*track_id, *audio_id, clip.trim_range(internal_start, internal_end));
                             }
                             _ => return Err("Expected audio instance ID for sampled clip".to_string()),
                         }
                     }
-                    AudioClipType::Recording => {
+                    ResolvedContent::Recording => {
                         // Recording clips cannot be trimmed - skip
                     }
                 }
@@ -569,7 +631,7 @@ mod tests {
 
         let mut clip_instance = ClipInstance::new(clip_id);
         clip_instance.timeline_start = Beats::ZERO;
-        clip_instance.trim_start = 0.0;
+        clip_instance.trim_start = ContentTime::ZERO;
         let instance_id = clip_instance.id;
         vector_layer.clip_instances.push(clip_instance);
 
@@ -582,8 +644,8 @@ mod tests {
             vec![(
                 instance_id,
                 TrimType::TrimLeft,
-                TrimData::left(0.0, Beats::ZERO),
+                TrimData::left(ContentTime::ZERO, Beats::ZERO),
-                TrimData::left(2.0, Beats(2.0)),
+                TrimData::left(ContentTime(2.0), Beats(2.0)),
             )],
         );
 
@@ -599,7 +661,7 @@ mod tests {
                 .iter()
                 .find(|ci| ci.id == instance_id)
                 .unwrap();
-            assert_eq!(instance.trim_start, 2.0);
+            assert_eq!(instance.trim_start, ContentTime(2.0));
             assert_eq!(instance.timeline_start, Beats(2.0));
         }
 
@@ -613,7 +675,7 @@ mod tests {
                 .iter()
                 .find(|ci| ci.id == instance_id)
                 .unwrap();
-            assert_eq!(instance.trim_start, 0.0);
+            assert_eq!(instance.trim_start, ContentTime::ZERO);
             assert_eq!(instance.timeline_start, Beats::ZERO);
         }
     }
@@ -644,7 +706,7 @@ mod tests {
                 instance_id,
                 TrimType::TrimRight,
                 TrimData::right(None),
-                TrimData::right(Some(8.0)),
+                TrimData::right(Some(ContentTime(8.0))),
             )],
         );
 
@@ -660,7 +722,7 @@ mod tests {
                 .iter()
                 .find(|ci| ci.id == instance_id)
                 .unwrap();
-            assert_eq!(instance.trim_end, Some(8.0));
+            assert_eq!(instance.trim_end, Some(ContentTime(8.0)));
         }
 
         // Rollback

lightningbeam-ui/lightningbeam-core/src/clip.rs

@@ -14,7 +14,7 @@
 use crate::layer::AnyLayer;
 use crate::layer_tree::LayerTree;
 use crate::object::Transform;
-use daw_backend::{Beats, Seconds};
+use daw_backend::{Beats, ContentTime, Seconds};
 use serde::{Deserialize, Serialize};
 use std::path::PathBuf;
 use uuid::Uuid;
@@ -130,10 +130,14 @@ impl VectorClip {
                 let end_beats: Beats = if let Some(td_beats) = ci.timeline_duration {
                     ci.timeline_start + td_beats
                 } else if let Some(te) = ci.trim_end {
-                    let secs = (te - ci.trim_start).max(0.0);
+                    // `clip_duration_fn` hands back seconds, so this whole path treats nested
+                    // content as wall-clock. That's right for the vector/video/audio clips a vector
+                    // clip actually nests; a nested MIDI clip (beats content) would need resolving
+                    // against its clip, which this callback can't do. Pre-existing limitation.
+                    let secs = (te - ci.trim_start).raw().max(0.0);
                     tempo_map.seconds_to_beats(tempo_map.beats_to_seconds(ci.timeline_start) + Seconds(secs))
                 } else if let Some(clip_dur_secs) = clip_duration_fn(&ci.clip_id) {
-                    let secs = (clip_dur_secs - ci.trim_start).max(0.0);
+                    let secs = (clip_dur_secs - ci.trim_start.raw()).max(0.0);
                     tempo_map.seconds_to_beats(tempo_map.beats_to_seconds(ci.timeline_start) + Seconds(secs))
                 } else {
                     continue;
@@ -201,7 +205,9 @@ impl VectorClip {
                     // Convert parent clip time (seconds) to nested clip local time (seconds).
                     // timeline_start is in beats; convert to seconds using document BPM.
                     let start_secs = document.tempo_map().beats_to_seconds(clip_instance.timeline_start).seconds_to_f64();
-                    let nested_clip_time = ((clip_time - start_secs) * clip_instance.playback_speed) + clip_instance.trim_start;
+                    // Nested clips here are vector clips, whose content is wall-clock seconds.
+                    let nested_clip_time =
+                        ((clip_time - start_secs) * clip_instance.playback_speed) + clip_instance.trim_start.raw();
 
                     // Look up the nested clip definition
                     let nested_bounds = if let Some(nested_clip) = document.get_vector_clip(&clip_instance.clip_id) {
@@ -468,6 +474,25 @@ pub enum AudioClipType {
     Recording,
 }
 
+/// One take of a cycle recording — see [`ClipInstance::takes`].
+#[derive(Clone, Debug, Serialize, Deserialize)]
+pub struct AudioTake {
+    /// Display name, e.g. "Take 1". User-editable.
+    pub name: String,
+    /// The recorded content this take points at.
+    pub content: TakeContent,
+}
+
+/// What a take actually holds. An instance's takes are all the same kind — one cycle-record session
+/// captures either audio or MIDI, never a mix.
+#[derive(Clone, Copy, Debug, PartialEq, Serialize, Deserialize)]
+pub enum TakeContent {
+    /// Sampled audio: index into the audio pool.
+    Audio { audio_pool_index: usize },
+    /// MIDI: backend MIDI clip ID.
+    Midi { midi_clip_id: u32 },
+}
+
 /// A clip's content duration, tagged by its native unit.
 ///
 /// Sampled/recording audio and video measure content in wall-clock **seconds**; MIDI measures
@@ -497,6 +522,17 @@ impl ClipDuration {
             ClipDuration::Beats(b) => b.beats_to_f64(),
         }
     }
+
+    /// Tag a [`ContentTime`] with *this* duration's domain.
+    ///
+    /// Handy when you already hold a clip's content duration (so you know the domain) and need to
+    /// resolve one of its trim bounds, without going back to the clip.
+    pub fn same_domain(self, t: ContentTime) -> ClipDuration {
+        match self {
+            ClipDuration::Seconds(_) => ClipDuration::Seconds(Seconds(t.raw())),
+            ClipDuration::Beats(_) => ClipDuration::Beats(Beats(t.raw())),
+        }
+    }
 }
 
 /// Audio clip
@@ -532,11 +568,10 @@ impl AudioClip {
     /// The clip's content duration, tagged with its native domain (seconds for sampled/recording,
     /// beats for MIDI). This is the only sanctioned way to read the raw `duration` field.
     pub fn content_duration(&self) -> ClipDuration {
-        match self.clip_type {
+        if self.is_midi_domain() {
-            AudioClipType::Midi { .. } => ClipDuration::Beats(Beats(self.duration)),
+            ClipDuration::Beats(Beats(self.duration))
-            AudioClipType::Sampled { .. } | AudioClipType::Recording => {
+        } else {
-                ClipDuration::Seconds(Seconds(self.duration))
+            ClipDuration::Seconds(Seconds(self.duration))
-            }
         }
     }
 
@@ -545,15 +580,19 @@ impl AudioClip {
     pub fn set_content_duration(&mut self, duration: ClipDuration) {
         debug_assert!(
             matches!(
-                (&self.clip_type, duration),
+                (self.is_midi_domain(), duration),
-                (AudioClipType::Midi { .. }, ClipDuration::Beats(_))
+                (true, ClipDuration::Beats(_)) | (false, ClipDuration::Seconds(_))
-                    | (AudioClipType::Sampled { .. } | AudioClipType::Recording, ClipDuration::Seconds(_))
             ),
             "clip duration domain must match clip type",
         );
         self.duration = duration.native();
     }
 
+    /// Whether this clip's `duration` is measured in beats (MIDI) rather than seconds.
+    fn is_midi_domain(&self) -> bool {
+        matches!(self.clip_type, AudioClipType::Midi { .. })
+    }
+
     /// Create a new sampled audio clip
     ///
     /// # Arguments
@@ -637,6 +676,73 @@ impl AudioClip {
             _ => None,
         }
     }
+
+    /// The clip's own content, ignoring takes.
+    ///
+    /// Callers that are handing content to the backend want [`ClipInstance::resolve`] instead — an
+    /// instance with takes overrides the clip's content with whichever take is active.
+    pub fn resolve(&self) -> ResolvedContent {
+        match &self.clip_type {
+            AudioClipType::Sampled { audio_pool_index } => ResolvedContent::Audio {
+                audio_pool_index: *audio_pool_index,
+            },
+            AudioClipType::Midi { midi_clip_id } => ResolvedContent::Midi {
+                midi_clip_id: *midi_clip_id,
+            },
+            AudioClipType::Recording => ResolvedContent::Recording,
+        }
+    }
+
+    /// Resolve a content time against this clip's domain.
+    ///
+    /// This is the ONLY sanctioned way to turn a [`ContentTime`] into a real duration — the type has
+    /// no `.to_seconds()` of its own precisely so that the clip, which is the one thing that knows
+    /// whether its content is measured in seconds or beats, has to be consulted.
+    pub fn resolve_content_time(&self, t: ContentTime) -> ClipDuration {
+        if self.is_midi_domain() {
+            ClipDuration::Beats(Beats(t.raw()))
+        } else {
+            ClipDuration::Seconds(Seconds(t.raw()))
+        }
+    }
+
+    /// Tag a pair of trim bounds with this clip's content domain, ready for the backend.
+    ///
+    /// Building the [`TrimRange`] from the clip means a caller can't reach for the wrong variant:
+    /// the clip is the one thing that knows the domain.
+    pub fn trim_range(&self, start: ContentTime, end: ContentTime) -> daw_backend::command::TrimRange {
+        if self.is_midi_domain() {
+            daw_backend::command::TrimRange::Beats {
+                start: Beats(start.raw()),
+                end: Beats(end.raw()),
+            }
+        } else {
+            daw_backend::command::TrimRange::Seconds {
+                start: Seconds(start.raw()),
+                end: Seconds(end.raw()),
+            }
+        }
+    }
+
+    /// Whether this clip's own content is the given audio pool index.
+    pub fn owns_audio_pool_index(&self, pool_index: usize) -> bool {
+        self.audio_pool_index() == Some(pool_index)
+    }
+
+    /// Whether this clip's own content is the given backend MIDI clip ID.
+    pub fn owns_midi_clip_id(&self, id: u32) -> bool {
+        self.midi_clip_id() == Some(id)
+    }
+}
+
+/// What a clip instance actually plays, once takes are resolved to the active one.
+/// Produced by [`ClipInstance::resolve`].
+#[derive(Clone, Copy, Debug, PartialEq)]
+pub enum ResolvedContent {
+    Audio { audio_pool_index: usize },
+    Midi { midi_clip_id: u32 },
+    /// A recording in progress (or an empty take folder) — no backend content yet.
+    Recording,
 }
 
 /// Unified clip enum for polymorphic handling
@@ -715,16 +821,17 @@ pub struct ClipInstance {
     /// Default: None (use trimmed clip duration, no looping)
     pub timeline_duration: Option<Beats>,
 
-    /// Trim start: offset into the clip's internal content, in **seconds**.
+    /// Trim start: offset into the clip's internal content.
-    /// - For audio: byte-offset into the audio file
+    ///
-    /// - For video: seek position in the video file
+    /// A [`ContentTime`] — measured in the CLIP's content domain, which is seconds for sampled
-    /// - For vector: time offset into the animation
+    /// audio/video/vector but BEATS for MIDI. Resolve it against the clip
+    /// ([`Document::resolve_content_time`]) before combining it with anything on the timeline.
     /// Default: 0.0
-    pub trim_start: f64,
+    pub trim_start: ContentTime,
 
-    /// Trim end: offset into the clip's internal content, in **seconds**.
+    /// Trim end: offset into the clip's internal content. See [`Self::trim_start`].
     /// Default: None (use full clip duration)
-    pub trim_end: Option<f64>,
+    pub trim_end: Option<ContentTime>,
 
     /// Playback speed multiplier
     /// 1.0 = normal speed, 0.5 = half speed, 2.0 = double speed
@@ -741,6 +848,35 @@ pub struct ClipInstance {
     /// Default: None (no pre-loop)
     #[serde(default, skip_serializing_if = "Option::is_none")]
     pub loop_before: Option<Beats>,
+
+    /// Alternate takes from cycle recording. Empty = an ordinary instance with no takes.
+    ///
+    /// The takes live on the INSTANCE, not the clip, so managing them is per-instance: deleting or
+    /// renaming a take on one instance leaves every other instance alone. Splitting clones the list
+    /// along with the rest of the instance, so the two halves get independent take lists — and,
+    /// since they can each select a different take, comping still falls out for free.
+    ///
+    /// Every take spans the full cycle region (partial passes are padded with silence at capture
+    /// time), so they're all the same length as the clip's own content. That uniformity is what lets
+    /// a take switch leave the instance's geometry untouched.
+    ///
+    /// When non-empty, these OVERRIDE the clip's own content — see [`Self::resolve`].
+    #[serde(default, skip_serializing_if = "Vec::is_empty")]
+    pub takes: Vec<AudioTake>,
+
+    /// Which of [`Self::takes`] plays. `None` (or a stale index) means take 0.
+    /// Default: None
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub active_take: Option<usize>,
+
+    /// The cycle region's length in beats when these takes were recorded.
+    ///
+    /// Audio takes are cut geometrically (by sample count), so they're only meaningful against the
+    /// tempo they were recorded at. Keeping the recorded length lets a future time-stretch/conform
+    /// feature reconcile them if the tempo moves underneath, and lets a new recording tell whether
+    /// it belongs in this take list or a fresh one.
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub recorded_loop_beats: Option<Beats>,
 }
 
 /// High 64-bit sentinel used to identify UUIDs that encode a backend audio clip instance ID.
@@ -794,11 +930,14 @@ impl ClipInstance {
             name: None,
             timeline_start: Beats::ZERO,
             timeline_duration: None,
-            trim_start: 0.0,
+            trim_start: ContentTime::ZERO,
             trim_end: None,
             playback_speed: 1.0,
             gain: 1.0,
             loop_before: None,
+            takes: Vec::new(),
+            active_take: None,
+            recorded_loop_beats: None,
         }
     }
 
@@ -812,11 +951,14 @@ impl ClipInstance {
             name: None,
             timeline_start: Beats::ZERO,
             timeline_duration: None,
-            trim_start: 0.0,
+            trim_start: ContentTime::ZERO,
             trim_end: None,
             playback_speed: 1.0,
             gain: 1.0,
             loop_before: None,
+            takes: Vec::new(),
+            active_take: None,
+            recorded_loop_beats: None,
         }
     }
 
@@ -852,7 +994,7 @@ impl ClipInstance {
     }
 
     /// Set trimming (start and end time within the clip's internal content)
-    pub fn with_trimming(mut self, trim_start: f64, trim_end: Option<f64>) -> Self {
+    pub fn with_trimming(mut self, trim_start: ContentTime, trim_end: Option<ContentTime>) -> Self {
         self.trim_start = trim_start;
         self.trim_end = trim_end;
         self
@@ -876,24 +1018,89 @@ impl ClipInstance {
         self
     }
 
-    /// Content window size in seconds: `trim_end - trim_start`.
+    /// The take this instance plays, if it has any.
+    ///
+    /// A `None`/stale `active_take` falls back to take 0 — an index can go stale (an undo that
+    /// shrank the list, an old `.beam`), and silently playing the first take beats playing nothing.
+    pub fn active_take(&self) -> Option<&AudioTake> {
+        self.takes
+            .get(self.active_take.unwrap_or(0))
+            .or_else(|| self.takes.first())
+    }
+
+    /// The index [`Self::active_take`] actually resolves to, clamped into range.
+    pub fn active_take_index(&self) -> usize {
+        let i = self.active_take.unwrap_or(0);
+        if i < self.takes.len() { i } else { 0 }
+    }
+
+    /// What this instance plays: its active take if it has takes, otherwise the clip's own content.
+    ///
+    /// This is the sanctioned way to ask "what content do I hand the backend for this instance?".
+    /// Takes are never a distinct *case* at the call site — an instance with takes is just an audio
+    /// or MIDI instance whose identity depends on which take is live.
+    pub fn resolve(&self, clip: &AudioClip) -> ResolvedContent {
+        match self.active_take().map(|t| &t.content) {
+            Some(TakeContent::Audio { audio_pool_index }) => ResolvedContent::Audio {
+                audio_pool_index: *audio_pool_index,
+            },
+            Some(TakeContent::Midi { midi_clip_id }) => ResolvedContent::Midi {
+                midi_clip_id: *midi_clip_id,
+            },
+            None => clip.resolve(),
+        }
+    }
+
+    /// The audio pool index this instance plays. See [`Self::resolve`].
+    pub fn resolved_audio_pool_index(&self, clip: &AudioClip) -> Option<usize> {
+        match self.resolve(clip) {
+            ResolvedContent::Audio { audio_pool_index } => Some(audio_pool_index),
+            _ => None,
+        }
+    }
+
+    /// The backend MIDI clip ID this instance plays. See [`Self::resolve`].
+    pub fn resolved_midi_clip_id(&self, clip: &AudioClip) -> Option<u32> {
+        match self.resolve(clip) {
+            ResolvedContent::Midi { midi_clip_id } => Some(midi_clip_id),
+            _ => None,
+        }
+    }
+
+    /// Content window (`trim_end - trim_start`) in the clip's own content domain.
     /// Used for internal looping calculations.
-    pub fn content_window_secs(&self, clip_duration_secs: Seconds) -> Seconds {
+    pub fn content_window(&self, clip_content: ClipDuration) -> ClipDuration {
-        let end = self.trim_end.unwrap_or(clip_duration_secs.seconds_to_f64());
+        let end = self.trim_end.map_or(clip_content.native(), |t| t.raw());
-        Seconds((end - self.trim_start).max(0.0))
+        let window = (end - self.trim_start.raw()).max(0.0);
+        match clip_content {
+            ClipDuration::Beats(_) => ClipDuration::Beats(Beats(window)),
+            ClipDuration::Seconds(_) => ClipDuration::Seconds(Seconds(window)),
+        }
     }
 
     /// How long this instance appears on the timeline, in **beats**.
     ///
-    /// If `timeline_duration` is set, returns that (enabling content looping).
+    /// If `timeline_duration` is set, returns that (enabling content looping). Otherwise the clip
-    /// Otherwise converts the content window from seconds to beats using the tempo map.
+    /// occupies its content window — converted to beats *in the clip's own domain*:
-    pub fn effective_duration_beats(&self, clip_duration_secs: Seconds, tempo_map: &crate::tempo_map::TempoMap) -> Beats {
+    ///
+    /// - MIDI content is already beats and is tempo-invariant, so it carries over directly.
+    /// - Wall-clock content (audio/video/vector) is a seconds span, so it converts at the clip's
+    ///   position on the timeline.
+    ///
+    /// Taking a `ClipDuration` rather than a bare `Seconds` is what keeps those apart: this used to
+    /// take seconds and subtract `trim_start` from it, which for a TRIMMED MIDI clip subtracted a
+    /// beats offset from a seconds duration and got the clip's length wrong.
+    pub fn effective_duration_beats(&self, clip_content: ClipDuration, tempo_map: &crate::tempo_map::TempoMap) -> Beats {
         if let Some(td) = self.timeline_duration {
             return td;
         }
-        let window = self.content_window_secs(clip_duration_secs);
+        match self.content_window(clip_content) {
-        let start_secs = tempo_map.beats_to_seconds(self.timeline_start);
+            ClipDuration::Beats(b) => b,
-        tempo_map.seconds_to_beats(start_secs + window) - self.timeline_start
+            ClipDuration::Seconds(s) => {
+                let start_secs = tempo_map.beats_to_seconds(self.timeline_start);
+                tempo_map.seconds_to_beats(start_secs + s) - self.timeline_start
+            }
+        }
     }
 
     /// Left edge of the clip's visual extent on the timeline, in **beats**.
@@ -902,27 +1109,32 @@ impl ClipInstance {
     }
 
     /// Total visual duration (loop_before + effective_duration), in **beats**.
-    pub fn total_duration(&self, clip_duration_secs: Seconds, tempo_map: &crate::tempo_map::TempoMap) -> Beats {
+    pub fn total_duration(&self, clip_content: ClipDuration, tempo_map: &crate::tempo_map::TempoMap) -> Beats {
-        self.loop_before.unwrap_or(Beats::ZERO) + self.effective_duration_beats(clip_duration_secs, tempo_map)
+        self.loop_before.unwrap_or(Beats::ZERO) + self.effective_duration_beats(clip_content, tempo_map)
     }
 
     /// Map a playback time (in **seconds**) to clip-local content time (in **seconds**).
     ///
-    /// Returns `None` if the clip instance is not active at `time_secs`.
+    /// The trim bounds are resolved through `clip_content`'s domain first, so a MIDI clip's beats
-    pub fn remap_time_secs(&self, time: Seconds, clip_duration_secs: Seconds, tempo_map: &crate::tempo_map::TempoMap) -> Option<Seconds> {
+    /// trims are converted rather than read as seconds. Callers are the wall-clock consumers (video
+    /// seek, vector/raster rendering), which want seconds regardless of how the clip stores content.
+    ///
+    /// Returns `None` if the clip instance is not active at `time`.
+    pub fn remap_time_secs(&self, time: Seconds, clip_content: ClipDuration, tempo_map: &crate::tempo_map::TempoMap) -> Option<Seconds> {
         let start_secs = tempo_map.beats_to_seconds(self.timeline_start);
-        let dur_beats = self.effective_duration_beats(clip_duration_secs, tempo_map);
+        let dur_beats = self.effective_duration_beats(clip_content, tempo_map);
         let end_secs = tempo_map.beats_to_seconds(self.timeline_start + dur_beats);
 
         if time < start_secs || time >= end_secs {
             return None;
         }
 
+        let trim_start_secs = clip_content.same_domain(self.trim_start).to_seconds(tempo_map);
         let content_time = (time - start_secs) * self.playback_speed;
-        let content_window = self.content_window_secs(clip_duration_secs);
+        let content_window = self.content_window(clip_content).to_seconds(tempo_map);
 
         if content_window == Seconds::ZERO {
-            return Some(Seconds(self.trim_start));
+            return Some(trim_start_secs);
         }
 
         let looped = if content_time > content_window {
@@ -931,19 +1143,19 @@ impl ClipInstance {
             content_time
         };
 
-        Some(Seconds(self.trim_start) + looped)
+        Some(trim_start_secs + looped)
     }
 
     /// Alias for `remap_time_secs`.
     #[inline]
-    pub fn remap_time(&self, time: Seconds, clip_duration_secs: Seconds, tempo_map: &crate::tempo_map::TempoMap) -> Option<Seconds> {
+    pub fn remap_time(&self, time: Seconds, clip_content: ClipDuration, tempo_map: &crate::tempo_map::TempoMap) -> Option<Seconds> {
-        self.remap_time_secs(time, clip_duration_secs, tempo_map)
+        self.remap_time_secs(time, clip_content, tempo_map)
     }
 
     /// Alias for `effective_duration_beats`.
     #[inline]
-    pub fn effective_duration(&self, clip_duration_secs: Seconds, tempo_map: &crate::tempo_map::TempoMap) -> Beats {
+    pub fn effective_duration(&self, clip_content: ClipDuration, tempo_map: &crate::tempo_map::TempoMap) -> Beats {
-        self.effective_duration_beats(clip_duration_secs, tempo_map)
+        self.effective_duration_beats(clip_content, tempo_map)
     }
 
     /// Convert to affine transform
@@ -1020,7 +1232,7 @@ mod tests {
         assert_eq!(instance.clip_id, clip_id);
         assert_eq!(instance.opacity, 1.0);
         assert_eq!(instance.timeline_start, Beats::ZERO);
-        assert_eq!(instance.trim_start, 0.0);
+        assert_eq!(instance.trim_start, ContentTime::ZERO);
         assert_eq!(instance.trim_end, None);
         assert_eq!(instance.playback_speed, 1.0);
         assert_eq!(instance.gain, 1.0);
@@ -1030,27 +1242,52 @@ mod tests {
     fn test_clip_instance_trimming() {
         let clip_id = Uuid::new_v4();
         let instance = ClipInstance::new(clip_id)
-            .with_trimming(2.0, Some(8.0));
+            .with_trimming(ContentTime(2.0), Some(ContentTime(8.0)));
 
-        assert_eq!(instance.trim_start, 2.0);
+        assert_eq!(instance.trim_start, ContentTime(2.0));
-        assert_eq!(instance.trim_end, Some(8.0));
+        assert_eq!(instance.trim_end, Some(ContentTime(8.0)));
         // At 60 BPM the tempo map is identity (1 beat == 1 second), so the
         // beats-domain effective duration equals the seconds content window.
         let tempo_map = crate::tempo_map::TempoMap::constant(60.0);
-        assert_eq!(instance.effective_duration(Seconds(10.0), &tempo_map), Beats(6.0));
+        let content = ClipDuration::Seconds(Seconds(10.0));
+        assert_eq!(instance.effective_duration(content, &tempo_map), Beats(6.0));
     }
 
     #[test]
     fn test_clip_instance_no_end_trim() {
         let clip_id = Uuid::new_v4();
         let instance = ClipInstance::new(clip_id)
-            .with_trimming(2.0, None);
+            .with_trimming(ContentTime(2.0), None);
 
-        assert_eq!(instance.trim_start, 2.0);
+        assert_eq!(instance.trim_start, ContentTime(2.0));
         assert_eq!(instance.trim_end, None);
         // At 60 BPM the tempo map is identity (1 beat == 1 second).
         let tempo_map = crate::tempo_map::TempoMap::constant(60.0);
-        assert_eq!(instance.effective_duration(Seconds(10.0), &tempo_map), Beats(8.0));
+        let content = ClipDuration::Seconds(Seconds(10.0));
+        assert_eq!(instance.effective_duration(content, &tempo_map), Beats(8.0));
+    }
+
+    #[test]
+    fn trimmed_midi_clip_keeps_its_beats_length_across_tempo() {
+        // Regression: `effective_duration_beats` used to take a SECONDS clip duration and subtract
+        // `trim_start` from it. For a TRIMMED MIDI clip that subtracted a beats offset from a
+        // seconds duration, so the clip's timeline length came out wrong at any tempo but 60 BPM.
+        //
+        // MIDI content is beats and tempo-invariant: a clip trimmed to beats 2..6 is 4 beats long
+        // whatever the tempo says.
+        let clip_id = Uuid::new_v4();
+        let instance = ClipInstance::new(clip_id)
+            .with_trimming(ContentTime(2.0), Some(ContentTime(6.0)));
+        let content = ClipDuration::Beats(Beats(8.0));
+
+        for bpm in [60.0, 120.0, 90.0] {
+            let tempo_map = crate::tempo_map::TempoMap::constant(bpm);
+            assert_eq!(
+                instance.effective_duration(content, &tempo_map),
+                Beats(4.0),
+                "a MIDI clip trimmed to beats 2..6 is 4 beats long at {bpm} BPM",
+            );
+        }
     }
 
     #[test]
@@ -1070,4 +1307,109 @@ mod tests {
         assert_eq!(instance.playback_speed, 2.0);
         assert_eq!(instance.gain, 0.8);
     }
+
+    /// A clip whose own content is pool 10, plus an instance carrying takes over the given pools.
+    fn with_takes(pool_indices: &[usize]) -> (AudioClip, ClipInstance) {
+        let clip = AudioClip::new_sampled("Cycle rec", pool_indices[0], 2.0);
+        let mut instance = ClipInstance::new(clip.id);
+        instance.takes = pool_indices
+            .iter()
+            .enumerate()
+            .map(|(i, &audio_pool_index)| AudioTake {
+                name: format!("Take {}", i + 1),
+                content: TakeContent::Audio { audio_pool_index },
+            })
+            .collect();
+        instance.recorded_loop_beats = Some(Beats(8.0));
+        (clip, instance)
+    }
+
+    #[test]
+    fn active_take_selects_the_pool_file() {
+        let (clip, mut instance) = with_takes(&[10, 11, 12]);
+        instance.active_take = Some(0);
+        assert_eq!(instance.resolved_audio_pool_index(&clip), Some(10));
+        instance.active_take = Some(2);
+        assert_eq!(instance.resolved_audio_pool_index(&clip), Some(12));
+        // None means take 0.
+        instance.active_take = None;
+        assert_eq!(instance.resolved_audio_pool_index(&clip), Some(10));
+    }
+
+    #[test]
+    fn out_of_range_take_falls_back_to_the_first() {
+        // An index can go stale (an undo that shrank the list, an old .beam). Playing the first take
+        // beats playing nothing.
+        let (clip, mut instance) = with_takes(&[10, 11]);
+        instance.active_take = Some(99);
+        assert_eq!(instance.resolved_audio_pool_index(&clip), Some(10));
+        assert_eq!(instance.active_take_index(), 0);
+    }
+
+    #[test]
+    fn an_instance_without_takes_plays_the_clips_own_content() {
+        let clip = AudioClip::new_sampled("Plain", 42, 2.0);
+        let instance = ClipInstance::new(clip.id);
+        assert!(instance.takes.is_empty());
+        assert_eq!(instance.resolved_audio_pool_index(&clip), Some(42));
+    }
+
+    #[test]
+    fn midi_takes_resolve_to_midi_content() {
+        let clip = AudioClip::new_midi("Cycle rec", 7, Beats(4.0));
+        let mut instance = ClipInstance::new(clip.id);
+        instance.takes = vec![AudioTake {
+            name: "Take 1".into(),
+            content: TakeContent::Midi { midi_clip_id: 7 },
+        }];
+        assert_eq!(clip.content_duration(), ClipDuration::Beats(Beats(4.0)));
+        assert_eq!(instance.resolved_midi_clip_id(&clip), Some(7));
+        assert_eq!(instance.resolved_audio_pool_index(&clip), None);
+    }
+
+    #[test]
+    fn splitting_gives_each_half_an_independent_take_list() {
+        // Takes live on the INSTANCE, so a split (which clones the instance) hands each half its own
+        // list. Two consequences, both wanted: the halves can select different takes (comping), and
+        // deleting a take from one leaves the other alone.
+        let (clip, left_src) = with_takes(&[10, 11, 12]);
+        let mut left = left_src.clone();
+        let mut right = left_src.clone();
+        right.id = Uuid::new_v4();
+
+        left.active_take = Some(0);
+        right.active_take = Some(2);
+        assert_eq!(left.resolved_audio_pool_index(&clip), Some(10));
+        assert_eq!(right.resolved_audio_pool_index(&clip), Some(12));
+
+        // Delete take 2 (pool 11) from the left half only.
+        left.takes.remove(1);
+        assert_eq!(left.takes.len(), 2);
+        assert_eq!(right.takes.len(), 3, "the other half keeps its own takes");
+        assert_eq!(
+            right.resolved_audio_pool_index(&clip),
+            Some(12),
+            "and its selection still points where it did",
+        );
+    }
+
+    #[test]
+    fn clip_instance_without_active_take_deserializes() {
+        // Back-compat: .beam files written before take folders have no `active_take` field.
+        let json = r#"{
+            "id": "550e8400-e29b-41d4-a716-446655440000",
+            "clip_id": "550e8400-e29b-41d4-a716-446655440001",
+            "transform": {"x": 0.0, "y": 0.0, "rotation": 0.0, "scale_x": 1.0, "scale_y": 1.0, "skew_x": 0.0, "skew_y": 0.0},
+            "opacity": 1.0,
+            "name": null,
+            "timeline_start": 0.0,
+            "timeline_duration": null,
+            "trim_start": 0.0,
+            "trim_end": null,
+            "playback_speed": 1.0,
+            "gain": 1.0
+        }"#;
+        let instance: ClipInstance = serde_json::from_str(json).expect("old instances must load");
+        assert_eq!(instance.active_take, None);
+    }
 }

lightningbeam-ui/lightningbeam-core/src/document.rs

@@ -201,6 +201,17 @@ pub struct Document {
     #[serde(default)]
     pub time_signature: TimeSignature,
 
+    /// Transport cycle (loop) region, as `(start, end)` in **beats**.
+    ///
+    /// Authored in beats so it stays put musically when the tempo changes. `None` = no region set.
+    /// Saved with the project; `#[serde(default)]` keeps older `.beam` files loading.
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub cycle_region: Option<(Beats, Beats)>,
+
+    /// Whether the transport loops over `cycle_region`.
+    #[serde(default)]
+    pub cycle_enabled: bool,
+
     /// Master track (master bus + tempo automation lane).
     /// Stored separately from the root layer tree; shown in timeline when
     /// `show_master_track` is enabled in the editor state.
@@ -297,6 +308,8 @@ impl Default for Document {
             height: 1080.0,
             framerate: 60.0,
             time_signature: TimeSignature::default(),
+            cycle_region: None,
+            cycle_enabled: false,
             master_layer: {
                 let mut ml = GroupLayer::new_master(120.0);
                 ml.layer.id = uuid::Uuid::new_v4();
@@ -451,8 +464,11 @@ impl Document {
             let end_beats: Beats = if let Some(timeline_duration) = instance.timeline_duration {
                 instance.timeline_start + timeline_duration
             } else {
-                let trim_end = instance.trim_end.unwrap_or(clip_duration);
+                // `clip_duration` arrives as seconds (the recursive helper's signature), so this
-                let trimmed_secs = ((trim_end - instance.trim_start) / instance.playback_speed).max(0.0);
+                // path is the wall-clock one; MIDI content would need resolving against its clip.
+                let trim_end = instance.trim_end.map_or(clip_duration, |t| t.raw());
+                let trimmed_secs =
+                    ((trim_end - instance.trim_start.raw()) / instance.playback_speed).max(0.0);
                 let start_secs = tempo_map.beats_to_seconds(instance.timeline_start);
                 tempo_map.seconds_to_beats(start_secs + Seconds(trimmed_secs))
             };
@@ -767,16 +783,18 @@ impl Document {
     }
 
     /// Find the document audio clip (UUID + ref) that owns the given backend pool index.
+    /// A take folder owns one pool file per take, so any of them maps back to the folder.
     pub fn audio_clip_by_pool_index(&self, pool_index: usize) -> Option<(Uuid, &AudioClip)> {
         self.audio_clips.iter()
-            .find(|(_, c)| c.audio_pool_index() == Some(pool_index))
+            .find(|(_, c)| c.owns_audio_pool_index(pool_index))
             .map(|(&id, c)| (id, c))
     }
 
     /// Find the document audio clip (UUID + ref) that owns the given backend MIDI clip ID.
+    /// As above, a take folder owns one MIDI clip per take.
     pub fn audio_clip_by_midi_clip_id(&self, midi_clip_id: u32) -> Option<(Uuid, &AudioClip)> {
         self.audio_clips.iter()
-            .find(|(_, c)| c.midi_clip_id() == Some(midi_clip_id))
+            .find(|(_, c)| c.owns_midi_clip_id(midi_clip_id))
             .map(|(&id, c)| (id, c))
     }
 
@@ -898,6 +916,81 @@ impl Document {
     /// Searches through all clip libraries to find the clip and return its duration.
     /// For effect definitions, returns `EFFECT_DURATION` (f64::MAX) since effects
     /// have infinite internal duration.
+    /// A clip's content duration **in the domain its `trim_start`/`trim_end` are measured in**.
+    ///
+    /// Content time is domain-polymorphic exactly like `AudioClip::duration`: SECONDS for sampled
+    /// audio, video and vector, but BEATS for MIDI. Anything doing arithmetic against a trim value —
+    /// mapping a timeline position into the clip's content, say — has to work in that same domain,
+    /// and [`Self::get_clip_duration`] can't tell it which: that one always converts to seconds.
+    ///
+    /// Returns `None` for unknown clips.
+    pub fn clip_trim_duration(&self, clip_id: &Uuid) -> Option<crate::clip::ClipDuration> {
+        if let Some(clip) = self.audio_clips.get(clip_id) {
+            return Some(clip.content_duration());
+        }
+        // Everything else measures its content in wall-clock seconds.
+        self.get_clip_duration(clip_id).map(crate::clip::ClipDuration::Seconds)
+    }
+
+    /// Find an existing take folder on `layer_id` that a new cycle recording should be appended to.
+    ///
+    /// Cycle-recording over a region that already holds a take folder should ADD to that folder
+    /// rather than drop a second clip on top of it — otherwise the new takes are stranded in a
+    /// separate, overlapping clip and can't be auditioned against the ones already there.
+    ///
+    /// "The same region" means the instance starts at `loop_start` and its folder was recorded
+    /// against the same loop length. Matching the length too means resizing the cycle region starts
+    /// a fresh folder rather than appending takes of a different length to an existing one, which
+    /// would break the uniform-take invariant comping depends on.
+    ///
+    /// `exclude` is the in-progress recording's own instance, which is on the layer but isn't a
+    /// candidate. Returns the instance id.
+    pub fn take_folder_at(
+        &self,
+        layer_id: &Uuid,
+        loop_start: Beats,
+        loop_len: Beats,
+        exclude: &Uuid,
+    ) -> Option<Uuid> {
+        let Some(AnyLayer::Audio(audio_layer)) = self.get_layer(layer_id) else {
+            return None;
+        };
+        const EPS: f64 = 1e-6;
+        audio_layer.clip_instances.iter().find_map(|ci| {
+            if ci.id == *exclude
+                || ci.takes.is_empty()
+                || (ci.timeline_start - loop_start).beats_to_f64().abs() > EPS
+            {
+                return None;
+            }
+            let recorded = ci.recorded_loop_beats?;
+            ((recorded - loop_len).beats_to_f64().abs() < EPS).then_some(ci.id)
+        })
+    }
+
+    /// Resolve a [`ContentTime`] (a trim bound) against the clip it belongs to.
+    ///
+    /// The clip is the only thing that knows whether its content is measured in seconds or beats, so
+    /// this is the sanctioned exit from `ContentTime`. Works for every clip kind, not just audio.
+    /// Returns `None` for unknown clips.
+    pub fn resolve_content_time(
+        &self,
+        clip_id: &Uuid,
+        t: daw_backend::ContentTime,
+    ) -> Option<crate::clip::ClipDuration> {
+        if let Some(clip) = self.audio_clips.get(clip_id) {
+            return Some(clip.resolve_content_time(t));
+        }
+        if self.vector_clips.contains_key(clip_id)
+            || self.video_clips.contains_key(clip_id)
+            || self.effect_definitions.contains_key(clip_id)
+        {
+            // Wall-clock content.
+            return Some(crate::clip::ClipDuration::Seconds(Seconds(t.raw())));
+        }
+        None
+    }
+
     pub fn get_clip_duration(&self, clip_id: &Uuid) -> Option<Seconds> {
         if let Some(clip) = self.vector_clips.get(clip_id) {
             if clip.is_group {
@@ -951,9 +1044,9 @@ impl Document {
         };
 
         let instance = instances.iter().find(|inst| &inst.id == instance_id)?;
-        let clip_duration = self.get_clip_duration(&instance.clip_id)?;
+        // The clip's content duration in ITS OWN domain, so the trims resolve correctly for MIDI.
-        // End position on the timeline, in beats (convert the seconds content window via tempo map).
+        let clip_content = self.clip_trim_duration(&instance.clip_id)?;
-        Some(instance.timeline_start + instance.effective_duration_beats(clip_duration, self.tempo_map()))
+        Some(instance.timeline_start + instance.effective_duration_beats(clip_content, self.tempo_map()))
     }
 
     /// Check if a time range overlaps with any existing clip on the layer
@@ -993,13 +1086,14 @@ impl Document {
                 continue;
             }
 
-            // Calculate instance extent (accounting for loop_before)
+            // Calculate instance extent (accounting for loop_before). Content duration in the clip's
-            let Some(clip_duration) = self.get_clip_duration(&instance.clip_id) else {
+            // own domain, so the trims resolve correctly for MIDI.
+            let Some(clip_content) = self.clip_trim_duration(&instance.clip_id) else {
                 continue;
             };
 
             let instance_start = instance.effective_start();
-            let instance_end = instance.timeline_start + instance.effective_duration(clip_duration, self.tempo_map());
+            let instance_end = instance.timeline_start + instance.effective_duration(clip_content, self.tempo_map());
 
             // Check overlap: start_a < end_b AND start_b < end_a
             if start_time < instance_end && instance_start < end_time {
@@ -1056,7 +1150,7 @@ impl Document {
                 continue;
             }
 
-            if let Some(clip_dur) = self.get_clip_duration(&instance.clip_id) {
+            if let Some(clip_dur) = self.clip_trim_duration(&instance.clip_id) {
                 let inst_start = instance.effective_start();
                 let inst_end = instance.timeline_start + instance.effective_duration(clip_dur, self.tempo_map());
                 occupied_ranges.push((inst_start, inst_end, instance.id));
@@ -1152,7 +1246,7 @@ impl Document {
             if group_ids.contains(&inst.id) {
                 continue;
             }
-            if let Some(dur) = self.get_clip_duration(&inst.clip_id) {
+            if let Some(dur) = self.clip_trim_duration(&inst.clip_id) {
                 let start = inst.effective_start();
                 let end = inst.timeline_start + inst.effective_duration(dur, self.tempo_map());
                 non_group.push((start, end));
@@ -1226,9 +1320,8 @@ impl Document {
             }
 
             // Calculate other clip's extent (accounting for loop_before)
-            if let Some(clip_duration) = self.get_clip_duration(&other.clip_id) {
+            if let Some(clip_duration) = self.clip_trim_duration(&other.clip_id) {
                 let other_end = other.timeline_start + other.effective_duration(clip_duration, self.tempo_map());
-                // (clip_duration is Seconds via get_clip_duration; effective_duration converts.)
 
                 // If this clip is to the left and closer than current nearest
                 if other_end <= current_timeline_start && other_end > nearest_end {
@@ -1326,7 +1419,7 @@ impl Document {
                 continue;
             }
 
-            if let Some(clip_duration) = self.get_clip_duration(&other.clip_id) {
+            if let Some(clip_duration) = self.clip_trim_duration(&other.clip_id) {
                 let other_end = other.timeline_start + other.effective_duration(clip_duration, self.tempo_map());
 
                 if other_end <= current_effective_start && other_end > nearest_end {

lightningbeam-ui/lightningbeam-core/src/effect_layer.rs

@@ -152,7 +152,12 @@ impl EffectLayer {
         self.clip_instances
             .iter()
             .filter(|e| {
-                let end = e.timeline_start + e.effective_duration(daw_backend::Seconds(EFFECT_DURATION), tempo_map);
+                // Effects have an "infinite" wall-clock content length.
+                let end = e.timeline_start
+                    + e.effective_duration(
+                        crate::clip::ClipDuration::Seconds(daw_backend::Seconds(EFFECT_DURATION)),
+                        tempo_map,
+                    );
                 time_beats >= e.timeline_start && time_beats < end
             })
             .collect()

lightningbeam-ui/lightningbeam-core/src/hit_test.rs

@@ -3,7 +3,7 @@
 //! Provides functions for testing if points or rectangles intersect with
 //! vector graph elements and clip instances, taking into account transform hierarchies.
 
-use crate::clip::ClipInstance;
+use crate::clip::{ClipDuration, ClipInstance};
 use crate::vector_graph::{VertexId, EdgeId, FillId};
 use crate::layer::VectorLayer;
 use crate::shape::Shape;
@@ -260,7 +260,10 @@ pub fn hit_test_clip_instances(
     for clip_instance in clip_instances.iter().rev() {
         // Check time bounds: skip clip instances not active at this time
         // timeline_start/instance_end are in beats; convert timeline_time (seconds) to beats.
-        let clip_duration = document.get_clip_duration(&clip_instance.clip_id).unwrap_or(daw_backend::Seconds::ZERO);
+        // Hit-testing runs on vector/raster content, which is wall-clock seconds.
+        let clip_duration = ClipDuration::Seconds(
+            document.get_clip_duration(&clip_instance.clip_id).unwrap_or(daw_backend::Seconds::ZERO),
+        );
         let instance_end = clip_instance.timeline_start + clip_instance.effective_duration(clip_duration, tempo_map);
         let timeline_beats = tempo_map.seconds_to_beats(daw_backend::Seconds(timeline_time));
         if timeline_beats < clip_instance.timeline_start || timeline_beats >= instance_end {
@@ -269,7 +272,8 @@ pub fn hit_test_clip_instances(
 
         // clip_time is in seconds; offset from clip start (in seconds) + trim_start (seconds)
         let start_secs = tempo_map.beats_to_seconds(clip_instance.timeline_start).seconds_to_f64();
-        let clip_time = ((timeline_time - start_secs) * clip_instance.playback_speed) + clip_instance.trim_start;
+        let clip_time =
+            ((timeline_time - start_secs) * clip_instance.playback_speed) + clip_instance.trim_start.raw();
 
         let content_bounds = if let Some(vector_clip) = document.get_vector_clip(&clip_instance.clip_id) {
             vector_clip.calculate_content_bounds(document, clip_time)
@@ -304,7 +308,10 @@ pub fn hit_test_clip_instances_in_rect(
     for clip_instance in clip_instances {
         // Check time bounds: skip clip instances not active at this time
         // timeline_start/instance_end are in beats; convert timeline_time (seconds) to beats.
-        let clip_duration = document.get_clip_duration(&clip_instance.clip_id).unwrap_or(daw_backend::Seconds::ZERO);
+        // Hit-testing runs on vector/raster content, which is wall-clock seconds.
+        let clip_duration = ClipDuration::Seconds(
+            document.get_clip_duration(&clip_instance.clip_id).unwrap_or(daw_backend::Seconds::ZERO),
+        );
         let instance_end = clip_instance.timeline_start + clip_instance.effective_duration(clip_duration, tempo_map);
         let timeline_beats = tempo_map.seconds_to_beats(daw_backend::Seconds(timeline_time));
         if timeline_beats < clip_instance.timeline_start || timeline_beats >= instance_end {
@@ -312,7 +319,8 @@ pub fn hit_test_clip_instances_in_rect(
         }
 
         let start_secs = tempo_map.beats_to_seconds(clip_instance.timeline_start).seconds_to_f64();
-        let clip_time = ((timeline_time - start_secs) * clip_instance.playback_speed) + clip_instance.trim_start;
+        let clip_time =
+            ((timeline_time - start_secs) * clip_instance.playback_speed) + clip_instance.trim_start.raw();
 
         let content_bounds = if let Some(vector_clip) = document.get_vector_clip(&clip_instance.clip_id) {
             vector_clip.calculate_content_bounds(document, clip_time)

lightningbeam-ui/lightningbeam-core/src/renderer.rs

@@ -9,7 +9,7 @@
 //! The compositing mode enables proper per-layer opacity, blend modes, and effects.
 
 use crate::animation::TransformProperty;
-use crate::clip::{ClipInstance, ImageAsset};
+use crate::clip::{ClipDuration, ClipInstance, ImageAsset};
 use crate::document::Document;
 use daw_backend::Seconds;
 use crate::gpu::BlendMode;
@@ -568,7 +568,7 @@ pub fn render_layer_isolated(
             let tempo_map = document.tempo_map();
             for clip_instance in &video_layer.clip_instances {
                 let Some(video_clip) = document.video_clips.get(&clip_instance.clip_id) else { continue };
-                let Some(clip_time) = clip_instance.remap_time(Seconds(time), Seconds(video_clip.duration), tempo_map) else { continue };
+                let Some(clip_time) = clip_instance.remap_time(Seconds(time), ClipDuration::Seconds(Seconds(video_clip.duration)), tempo_map) else { continue };
                 let clip_time = clip_time.seconds_to_f64();
                 let Some(frame) = video_mgr.get_frame(&clip_instance.clip_id, clip_time, target_w, target_h) else { continue };
 
@@ -1019,7 +1019,10 @@ fn render_clip_instance(
         }
         0.0
     } else {
-        let clip_dur = document.get_clip_duration(&vector_clip.id).unwrap_or(Seconds(vector_clip.duration));
+        // A vector clip's content is wall-clock seconds.
+        let clip_dur = ClipDuration::Seconds(
+            document.get_clip_duration(&vector_clip.id).unwrap_or(Seconds(vector_clip.duration)),
+        );
         let Some(t) = clip_instance.remap_time(Seconds(time), clip_dur, tempo_map) else {
             return; // Clip instance not active at this time
         };
@@ -1174,7 +1177,7 @@ fn render_video_layer(
 
         // Remap timeline time to clip's internal time
         let tempo_map = document.tempo_map();
-        let Some(clip_time) = clip_instance.remap_time(Seconds(time), Seconds(video_clip.duration), tempo_map) else {
+        let Some(clip_time) = clip_instance.remap_time(Seconds(time), ClipDuration::Seconds(Seconds(video_clip.duration)), tempo_map) else {
             continue; // Clip instance not active at this time
         };
         let clip_time = clip_time.seconds_to_f64();
@@ -1910,7 +1913,10 @@ fn render_clip_instance_cpu(
         if time < start_secs || time >= end { return; }
         0.0
     } else {
-        let clip_dur = document.get_clip_duration(&vector_clip.id).unwrap_or(Seconds(vector_clip.duration));
+        // A vector clip's content is wall-clock seconds.
+        let clip_dur = ClipDuration::Seconds(
+            document.get_clip_duration(&vector_clip.id).unwrap_or(Seconds(vector_clip.duration)),
+        );
         let Some(t) = clip_instance.remap_time(Seconds(time), clip_dur, tempo_map) else { return };
         t.seconds_to_f64()
     };

lightningbeam-ui/lightningbeam-editor/src/config.rs

@@ -35,6 +35,18 @@ pub struct AppConfig {
     #[serde(default = "defaults::audio_buffer_size")]
     pub audio_buffer_size: u32,
 
+    /// How a cycle MIDI recording treats its passes.
+    ///
+    /// `false` (default) = **merge**: every pass overdubs into one clip, and earlier passes play back
+    /// as you record so you can layer against them. `true` = **separate takes**: each pass becomes
+    /// its own take in a take folder, exactly as audio always does, and earlier passes stay silent
+    /// (they're alternatives, not layers).
+    ///
+    /// Only applies when the transport actually wraps; a recording that stops inside the first pass
+    /// is an ordinary single recording either way.
+    #[serde(default = "defaults::cycle_midi_separate_takes")]
+    pub cycle_midi_separate_takes: bool,
+
     /// Reopen last session on startup
     #[serde(default = "defaults::reopen_last_session")]
     pub reopen_last_session: bool,
@@ -90,6 +102,7 @@ impl Default for AppConfig {
             file_height: defaults::file_height(),
             scroll_speed: defaults::scroll_speed(),
             audio_buffer_size: defaults::audio_buffer_size(),
+            cycle_midi_separate_takes: defaults::cycle_midi_separate_takes(),
             reopen_last_session: defaults::reopen_last_session(),
             restore_layout_from_file: defaults::restore_layout_from_file(),
             debug: defaults::debug(),
@@ -296,6 +309,7 @@ mod defaults {
     pub fn file_height() -> u32 { 600 }
     pub fn scroll_speed() -> f64 { 1.0 }
     pub fn audio_buffer_size() -> u32 { 256 }
+    pub fn cycle_midi_separate_takes() -> bool { false }
     pub fn reopen_last_session() -> bool { false }
     pub fn restore_layout_from_file() -> bool { true }
     pub fn debug() -> bool { false }

lightningbeam-ui/lightningbeam-editor/src/export/video_exporter.rs

@@ -1064,7 +1064,12 @@ fn composite_document_to_hdr(
                     }
                     let tempo_map = document.tempo_map();
                     let effect_end_beats = effect_instance.timeline_start
-                        + effect_instance.effective_duration(daw_backend::Seconds(lightningbeam_core::effect::EFFECT_DURATION), tempo_map);
+                        + effect_instance.effective_duration(
+                            lightningbeam_core::clip::ClipDuration::Seconds(daw_backend::Seconds(
+                                lightningbeam_core::effect::EFFECT_DURATION,
+                            )),
+                            tempo_map,
+                        );
                     let effect_inst = lightningbeam_core::effect::EffectInstance::new(
                         effect_def,
                         tempo_map.beats_to_seconds(effect_instance.timeline_start).seconds_to_f64(),

lightningbeam-ui/lightningbeam-editor/src/main.rs

@@ -1105,6 +1105,23 @@ impl EditingContext {
     }
 }
 
+/// A finished cycle recording whose takes belong to a take folder that already exists at that
+/// region, queued for [`EditorApp::append_cycle_takes`].
+struct PendingTakeAppend {
+    layer_id: Uuid,
+    /// The throwaway clip + instance the recording itself was captured into.
+    recording_instance_id: Uuid,
+    recording_clip_id: Uuid,
+    /// The recording's backend clip, which has to be torn down or it keeps playing alongside the
+    /// take folder we're appending to. Carried explicitly rather than looked up in
+    /// `clip_instance_to_backend_map`, because on the audio path the recording instance isn't in
+    /// that map yet — it's only added after promotion, which the append path skips.
+    recording_backend_id: Option<lightningbeam_core::action::BackendClipInstanceId>,
+    loop_start: Beats,
+    loop_len: Beats,
+    takes: Vec<lightningbeam_core::clip::AudioTake>,
+}
+
 struct EditorApp {
     layouts: Vec<LayoutDefinition>,
     current_layout_index: usize,
@@ -1213,6 +1230,10 @@ struct EditorApp {
     metronome_enabled: bool,              // Whether metronome clicks during recording
     count_in_enabled: bool,              // Whether count-in fires before recording
     recording_clips: HashMap<Uuid, u32>,  // layer_id -> backend clip_id during recording
+    /// Cycle takes waiting to be folded into an existing take folder. Queued from the audio-event
+    /// loop (which holds a borrow on the event queue, so it can't call a `&mut self` method) and
+    /// drained just after it.
+    pending_take_appends: Vec<PendingTakeAppend>,
     recording_start_time: f64,            // Playback time when recording started
     recording_layer_ids: Vec<Uuid>,       // Layers being recorded to (for creating clips)
     // Asset drag-and-drop state
@@ -1581,6 +1602,7 @@ impl EditorApp {
             metronome_enabled: false,         // Metronome off by default
             count_in_enabled: false,         // Count-in off by default
             recording_clips: HashMap::new(),  // No active recording clips
+            pending_take_appends: Vec::new(),
             recording_start_time: 0.0,        // Will be set when recording starts
             recording_layer_ids: Vec::new(),  // Will be populated when recording starts
             dragging_asset: None, // No asset being dragged initially
@@ -2036,9 +2058,113 @@ impl EditorApp {
     /// 2. For MIDI: Loads the default instrument
     /// 3. Stores the bidirectional mapping
     /// 4. Syncs any existing clips on the layer
+    /// Fold freshly-recorded cycle takes into an existing take folder covering the same region, if
+    /// there is one. Returns true if it did.
+    ///
+    /// Recording more takes over a region you've already recorded should extend that folder, not
+    /// stack a second clip on top of it — otherwise the new takes are stranded in an overlapping
+    /// clip and you can't audition them against the ones already there.
+    ///
+    /// The in-progress recording's own clip and instance are throwaway scaffolding in this case (the
+    /// takes themselves already live in the backend pools), so they're discarded. They were never
+    /// committed as an action, so there's nothing on the undo stack to unwind — the single
+    /// `AppendTakesAction` is the whole undoable step.
+    fn append_cycle_takes(
+        &mut self,
+        layer_id: uuid::Uuid,
+        recording_instance_id: uuid::Uuid,
+        recording_clip_id: uuid::Uuid,
+        recording_backend_id: Option<lightningbeam_core::action::BackendClipInstanceId>,
+        loop_start: Beats,
+        loop_len: Beats,
+        takes: Vec<lightningbeam_core::clip::AudioTake>,
+    ) -> bool {
+        let Some(target_instance_id) = self.action_executor.document().take_folder_at(
+            &layer_id,
+            loop_start,
+            loop_len,
+            &recording_instance_id,
+        ) else {
+            return false;
+        };
+
+        // Tear down the recording's own backend clip. Without this it keeps playing on top of the
+        // take folder we're appending to — two takes sounding at once. The target instance's clip is
+        // separately repointed at the new active take by the action's backend sync below.
+        let backend_id = recording_backend_id
+            .or_else(|| self.clip_instance_to_backend_map.remove(&recording_instance_id));
+        self.clip_instance_to_backend_map.remove(&recording_instance_id);
+        let track_id = self.layer_to_track_map.get(&layer_id).copied();
+        if let (Some(backend_id), Some(track_id), Some(controller_arc)) =
+            (backend_id, track_id, self.audio_controller.as_ref())
+        {
+            let mut controller = controller_arc.lock().unwrap();
+            match backend_id {
+                lightningbeam_core::action::BackendClipInstanceId::Audio(id) => {
+                    controller.remove_audio_clip(track_id, id)
+                }
+                lightningbeam_core::action::BackendClipInstanceId::Midi(id) => {
+                    controller.remove_midi_clip(track_id, id)
+                }
+            }
+        }
+
+        // Discard the scaffolding clip + instance.
+        {
+            let doc = self.action_executor.document_mut();
+            if let Some(AnyLayer::Audio(al)) = doc.get_layer_mut(&layer_id) {
+                al.clip_instances.retain(|ci| ci.id != recording_instance_id);
+            }
+            doc.audio_clips.remove(&recording_clip_id);
+        }
+
+        let action = lightningbeam_core::actions::AppendTakesAction::new(
+            layer_id,
+            target_instance_id,
+            takes,
+        );
+
+        if let Some(controller_arc) = self.audio_controller.clone() {
+            let mut controller = controller_arc.lock().unwrap();
+            let mut backend_context = lightningbeam_core::action::BackendContext {
+                audio_controller: Some(&mut *controller),
+                layer_to_track_map: &self.layer_to_track_map,
+                clip_instance_to_backend_map: &mut self.clip_instance_to_backend_map,
+            };
+            if let Err(e) = self
+                .action_executor
+                .execute_with_backend(Box::new(action), &mut backend_context)
+            {
+                eprintln!("Failed to append cycle takes: {}", e);
+            }
+        }
+
+        self.autosave.pending_event = true;
+        true
+    }
+
     fn sync_audio_layers_to_backend(&mut self) {
         use lightningbeam_core::layer::{AnyLayer, AudioLayerType};
 
+        // Push the document's cycle region to the engine. Needed on load/new: the region is
+        // document state, but the engine starts blank (and is cleared on Reset), so without this a
+        // loaded project would show its cycle strip while the transport never actually looped.
+        // Changes made later go through SetCycleRegionAction's execute_backend.
+        {
+            let (region, enabled) = {
+                let doc = self.action_executor.document();
+                (doc.cycle_region, doc.cycle_enabled)
+            };
+            if let Some(ref controller_arc) = self.audio_controller {
+                let mut controller = controller_arc.lock().unwrap();
+                controller.set_loop_region(region);
+                controller.set_loop_enabled(enabled);
+                // Cycle MIDI mode is a *preference*, not document state, so it rides along here
+                // rather than through an action.
+                controller.set_cycle_midi_separate_takes(self.config.cycle_midi_separate_takes);
+            }
+        }
+
         // Ensure the master layer has a backend group track.
         let master_layer_id = self.action_executor.document().master_layer.layer.id;
         if !self.layer_to_track_map.contains_key(&master_layer_id) {
@@ -2371,7 +2497,7 @@ impl EditorApp {
         ) -> Vec<uuid::Uuid> {
             let mut result = Vec::new();
             for instance in clip_instances {
-                if let Some(clip_duration) = document.get_clip_duration(&instance.clip_id) {
+                if let Some(clip_duration) = document.clip_trim_duration(&instance.clip_id) {
                     let effective_duration = instance.effective_duration(clip_duration, document.tempo_map());
                     let timeline_end = instance.timeline_start + effective_duration;
 
@@ -3260,7 +3386,9 @@ impl EditorApp {
             let duplicates: Vec<lightningbeam_core::clip::ClipInstance> = clips_to_duplicate.iter().map(|original| {
                 let mut duplicate = original.clone();
                 duplicate.id = uuid::Uuid::new_v4();
-                let clip_duration = document.get_clip_duration(&original.clip_id).unwrap_or(Seconds(1.0));
+                let clip_duration = document
+                    .clip_trim_duration(&original.clip_id)
+                    .unwrap_or(ClipDuration::Seconds(Seconds(1.0)));
                 let effective_duration = original.effective_duration(clip_duration, document.tempo_map());
                 duplicate.timeline_start = original.timeline_start + effective_duration;
                 if let Some((new_clip_def_id, _)) = midi_clip_replacements.get(&original.clip_id) {
@@ -5461,7 +5589,7 @@ impl EditorApp {
                     // matches the video clip exactly).
                     let (_dur, sample_rate, channels) = controller
                         .get_pool_file_info(pool_index)
-                        .unwrap_or((video_duration, 0, 0));
+                        .unwrap_or((Seconds(video_duration), 0, 0));
                     drop(controller);
 
                     let audio_clip_name = format!("{} (Audio)", video_name);
@@ -6368,7 +6496,9 @@ impl eframe::App for EditorApp {
                     use daw_backend::AudioEvent;
                     match event {
                         AudioEvent::PlaybackPosition(time) => {
-                            self.playback_time = time;
+                            // `playback_time` is the UI's seconds playhead (see the timeline's
+                            // seconds/beats model); unwrap at this boundary, not before it.
+                            self.playback_time = time.seconds_to_f64();
                         }
                         AudioEvent::PlaybackStopped => {
                             self.is_playing = false;
@@ -6474,6 +6604,25 @@ impl eframe::App for EditorApp {
                                         })
                                 };
 
+                                // While cycling, the recording keeps running but the clip only ever
+                                // occupies ONE region — each further pass is a new take layered on
+                                // the same span, not more length. Cap the preview there so the bar
+                                // doesn't grow off past the loop end while the playhead wraps.
+                                let cycle_cap = {
+                                    let doc = self.action_executor.document();
+                                    match (doc.cycle_enabled, doc.cycle_region) {
+                                        (true, Some((ls, le))) if le > ls => {
+                                            let tm = doc.tempo_map();
+                                            Some(tm.beats_to_seconds(le) - tm.beats_to_seconds(ls))
+                                        }
+                                        _ => None,
+                                    }
+                                };
+                                let duration = match cycle_cap {
+                                    Some(cap) if duration > cap => cap,
+                                    _ => duration,
+                                };
+
                                 // Then update the clip duration (mutable borrow)
                                 if let Some(doc_clip_id) = doc_clip_id {
                                     if let Some(clip) = self.action_executor.document_mut().audio_clips.get_mut(&doc_clip_id) {
@@ -6485,6 +6634,158 @@ impl eframe::App for EditorApp {
                             }
                             ctx.request_repaint();
                         }
+                        AudioEvent::CycleRecordingStopped { clip_id: backend_clip_id, takes, loop_start, loop_len_beats, loop_len_seconds } => {
+                            eprintln!("[STOP] CycleRecordingStopped: {} takes", takes.len());
+
+                            // Clean up the live-recording waveform cache (keyed usize::MAX).
+                            self.raw_audio_cache.remove(&usize::MAX);
+                            self.waveform_gpu_dirty.remove(&usize::MAX);
+
+                            // Pull every take's samples in for waveform rendering — the user can
+                            // switch to any of them, not just the active one.
+                            if let Some(ref controller_arc) = self.audio_controller {
+                                let mut controller = controller_arc.lock().unwrap();
+                                for &(pool_index, _) in &takes {
+                                    match controller.get_pool_audio_samples(pool_index) {
+                                        Ok((samples, sr, ch)) => {
+                                            self.raw_audio_cache.insert(pool_index, (Arc::new(samples), sr, ch));
+                                            self.waveform_gpu_dirty.insert(pool_index);
+                                            self.audio_pools_with_new_waveforms.insert(pool_index);
+                                        }
+                                        Err(e) => eprintln!("Failed to fetch take audio: {}", e),
+                                    }
+                                    self.audio_duration_cache.insert(pool_index, loop_len_seconds.seconds_to_f64());
+                                }
+                            }
+
+                            let recording_layer = self.recording_clips.iter()
+                                .find(|(_, &cid)| cid == backend_clip_id)
+                                .map(|(&lid, _)| lid);
+
+                            if let (Some(layer_id), false) = (recording_layer, takes.is_empty()) {
+                                let (clip_id, instance_id) = {
+                                    let document = self.action_executor.document();
+                                    document.get_layer(&layer_id)
+                                        .and_then(|layer| {
+                                            if let lightningbeam_core::layer::AnyLayer::Audio(audio_layer) = layer {
+                                                audio_layer.clip_instances.last().map(|i| (i.clip_id, i.id))
+                                            } else {
+                                                None
+                                            }
+                                        })
+                                        .unwrap_or((uuid::Uuid::nil(), uuid::Uuid::nil()))
+                                };
+
+                                if !clip_id.is_nil() {
+                                    self.autosave.pending_event = true;
+                                    let last_take = takes.len() - 1;
+
+                                    let new_takes: Vec<lightningbeam_core::clip::AudioTake> = takes
+                                        .iter()
+                                        .map(|&(pool_index, _)| lightningbeam_core::clip::AudioTake {
+                                            // Renumbered by the folder that ends up owning them.
+                                            name: String::new(),
+                                            content: lightningbeam_core::clip::TakeContent::Audio { audio_pool_index: pool_index },
+                                        })
+                                        .collect();
+
+                                    // If this region already holds a take folder, extend it rather
+                                    // than dropping a second clip on top. Queued and run just after
+                                    // this loop, which holds a borrow on the event queue.
+                                    if self.action_executor.document()
+                                        .take_folder_at(&layer_id, loop_start, loop_len_beats, &instance_id)
+                                        .is_some()
+                                    {
+                                        self.pending_take_appends.push(PendingTakeAppend {
+                                            layer_id,
+                                            recording_instance_id: instance_id,
+                                            recording_clip_id: clip_id,
+                                            // The engine's recording clip. It isn't in
+                                            // clip_instance_to_backend_map yet (that only happens on
+                                            // promotion, which we're skipping), so hand it over
+                                            // directly or it'll keep sounding alongside the folder.
+                                            recording_backend_id: Some(
+                                                lightningbeam_core::action::BackendClipInstanceId::Audio(backend_clip_id),
+                                            ),
+                                            loop_start,
+                                            loop_len: loop_len_beats,
+                                            takes: new_takes,
+                                        });
+                                        self.recording_clips.retain(|_, &mut cid| cid != backend_clip_id);
+                                        ctx.request_repaint();
+                                        continue;
+                                    }
+
+                                    // Finalize the recording clip, and hang the takes off the INSTANCE.
+                                    {
+                                        let doc = self.action_executor.document_mut();
+                                        if let Some(clip) = doc.audio_clips.get_mut(&clip_id) {
+                                            // The clip's own content is take 1; the instance's take
+                                            // list overrides it with whichever take is active. Every
+                                            // take is exactly one cycle region long, so the clip's
+                                            // duration is the region.
+                                            clip.finalize_recording(
+                                                takes[0].0,
+                                                loop_len_seconds.seconds_to_f64(),
+                                            );
+                                            clip.name = format!("Cycle recording ({} takes)", takes.len());
+                                        }
+
+                                        // Anchor the instance to the region and select the most
+                                        // recent take, GarageBand-style.
+                                        //
+                                        // timeline_duration stays None on purpose: pinning it would
+                                        // make a later tempo change loop/repeat the take's content
+                                        // to fill the span instead of letting it drift naturally.
+                                        if let Some(lightningbeam_core::layer::AnyLayer::Audio(al)) = doc.get_layer_mut(&layer_id) {
+                                            if let Some(inst) = al.clip_instances.iter_mut().find(|ci| ci.id == instance_id) {
+                                                inst.timeline_start = loop_start;
+                                                inst.timeline_duration = None;
+                                                // Audio take content is seconds, and each take spans
+                                                // exactly one cycle region.
+                                                inst.trim_start = daw_backend::ContentTime::ZERO;
+                                                inst.trim_end =
+                                                    Some(daw_backend::ContentTime(loop_len_seconds.seconds_to_f64()));
+                                                inst.takes = takes.iter().enumerate().map(|(i, &(pool_index, _))| {
+                                                    lightningbeam_core::clip::AudioTake {
+                                                        name: format!("Take {}", i + 1),
+                                                        content: lightningbeam_core::clip::TakeContent::Audio { audio_pool_index: pool_index },
+                                                    }
+                                                }).collect();
+                                                inst.active_take = Some(last_take);
+                                                inst.recorded_loop_beats = Some(loop_len_beats);
+                                            }
+                                        }
+                                    }
+
+                                    // The backend already has a clip for the active take (the engine
+                                    // pointed it at the last take on stop), so map to it rather than
+                                    // adding a duplicate.
+                                    let backend_id = lightningbeam_core::action::BackendClipInstanceId::Audio(backend_clip_id);
+                                    self.clip_instance_to_backend_map.insert(instance_id, backend_id);
+
+                                    // Commit the whole cycle-record session as ONE undoable action.
+                                    let clip_instance = self.layer_to_track_map.get(&layer_id).copied().and_then(|track_id| {
+                                        self.action_executor.document()
+                                            .get_layer(&layer_id)
+                                            .and_then(|l| if let AnyLayer::Audio(al) = l {
+                                                al.clip_instances.iter().find(|ci| ci.id == instance_id).cloned()
+                                            } else { None })
+                                            .map(|ci| (track_id, ci))
+                                    });
+                                    if let Some((track_id, clip_instance)) = clip_instance {
+                                        let action = lightningbeam_core::actions::AddClipInstanceAction::already_applied(
+                                            layer_id, clip_instance, track_id, backend_id,
+                                        );
+                                        self.action_executor.push_applied(Box::new(action));
+                                    } else {
+                                        self.media_modified = true;
+                                    }
+                                }
+                            }
+
+                            self.recording_clips.retain(|_, &mut cid| cid != backend_clip_id);
+                        }
                         AudioEvent::RecordingStopped(_backend_clip_id, pool_index, _waveform) => {
                             eprintln!("[STOP] AudioEvent::RecordingStopped received (pool_index={})", pool_index);
 
@@ -6510,6 +6811,7 @@ impl eframe::App for EditorApp {
                                 let mut controller = controller_arc.lock().unwrap();
                                 match controller.get_pool_file_info(pool_index) {
                                     Ok((dur, _, _)) => {
+                                        let dur = dur.seconds_to_f64();
                                         eprintln!("[AUDIO] Got duration from backend: {:.4}s", dur);
                                         self.audio_duration_cache.insert(pool_index, dur);
                                         dur
@@ -6543,7 +6845,7 @@ impl eframe::App for EditorApp {
                                                 None
                                             }
                                         })
-                                        .unwrap_or((uuid::Uuid::nil(), uuid::Uuid::nil(), Beats::ZERO, 0.0))
+                                        .unwrap_or((uuid::Uuid::nil(), uuid::Uuid::nil(), Beats::ZERO, daw_backend::ContentTime::ZERO))
                                 };
 
                                 if !clip_id.is_nil() {
@@ -6667,7 +6969,11 @@ impl eframe::App for EditorApp {
                                             );
                                         }
                                     }
-                                    // Update the clip's duration so the timeline bar grows
+                                    // Update the clip's duration so the timeline bar grows. Once the
+                                    // transport has wrapped, the backend reports the whole cycle
+                                    // region here and keeps reporting it, so the bar grows through
+                                    // the first pass and then holds — every further pass merges into
+                                    // the same clip rather than extending it.
                                     if let Some(clip) = self.action_executor.document_mut().audio_clips.get_mut(&doc_clip_id) {
                                         clip.set_content_duration(ClipDuration::Beats(duration));
                                     }
@@ -6687,6 +6993,144 @@ impl eframe::App for EditorApp {
                             }
                             ctx.request_repaint();
                         }
+                        AudioEvent::MidiCycleRecordingStopped { track_id, clip_ids, loop_start, loop_len_beats } => {
+                            println!("🎹 MIDI cycle recording stopped: {} takes", clip_ids.len());
+
+                            // Pull every take's events into the cache — the user can switch to any of
+                            // them, not just the active one.
+                            if let Some(ref controller_arc) = self.audio_controller {
+                                let mut controller = controller_arc.lock().unwrap();
+                                for &take_clip_id in &clip_ids {
+                                    if let Ok(data) = controller.query_midi_clip(track_id, take_clip_id) {
+                                        self.midi_event_cache.insert(take_clip_id, data.events);
+                                    }
+                                }
+                            }
+
+                            let layer_id = self.track_to_layer_map.get(&track_id).copied();
+                            if let (Some(layer_id), Some(&first_clip_id)) = (layer_id, clip_ids.first()) {
+                                // The doc clip is the one the recording started on — which the backend
+                                // reused as take 1.
+                                let doc_clip_id = self.action_executor.document()
+                                    .audio_clip_by_midi_clip_id(first_clip_id)
+                                    .map(|(id, _)| id);
+
+                                if let Some(doc_clip_id) = doc_clip_id {
+                                    self.autosave.pending_event = true;
+                                    let last_take = clip_ids.len() - 1;
+
+                                    let recording_instance_id = self.action_executor.document()
+                                        .get_layer(&layer_id)
+                                        .and_then(|l| if let AnyLayer::Audio(al) = l {
+                                            al.clip_instances.iter().find(|ci| ci.clip_id == doc_clip_id).map(|ci| ci.id)
+                                        } else { None });
+
+                                    let new_takes: Vec<lightningbeam_core::clip::AudioTake> = clip_ids
+                                        .iter()
+                                        .map(|&mid| lightningbeam_core::clip::AudioTake {
+                                            // Renumbered by the folder that ends up owning them.
+                                            name: String::new(),
+                                            content: lightningbeam_core::clip::TakeContent::Midi { midi_clip_id: mid },
+                                        })
+                                        .collect();
+
+                                    // If this region already holds a take folder, extend it rather
+                                    // than dropping a second clip on top. Queued and run just after
+                                    // this loop, which holds a borrow on the event queue.
+                                    let existing_folder = recording_instance_id.filter(|rec_inst| {
+                                        self.action_executor.document()
+                                            .take_folder_at(&layer_id, loop_start, loop_len_beats, rec_inst)
+                                            .is_some()
+                                    });
+                                    if let Some(rec_inst) = existing_folder {
+                                        self.pending_take_appends.push(PendingTakeAppend {
+                                            layer_id,
+                                            recording_instance_id: rec_inst,
+                                            recording_clip_id: doc_clip_id,
+                                            // The MIDI path maps its recording instance during
+                                            // MidiRecordingProgress, so the map has it.
+                                            recording_backend_id: None,
+                                            loop_start,
+                                            loop_len: loop_len_beats,
+                                            takes: new_takes,
+                                        });
+                                        self.recording_layer_ids.retain(|id| *id != layer_id);
+                                        self.recording_clips.remove(&layer_id);
+                                        if self.recording_layer_ids.is_empty() {
+                                            self.is_recording = false;
+                                            self.recording_clips.clear();
+                                        }
+                                        ctx.request_repaint();
+                                        continue;
+                                    }
+
+                                    {
+                                        let doc = self.action_executor.document_mut();
+                                        if let Some(clip) = doc.audio_clips.get_mut(&doc_clip_id) {
+                                            // The clip's own content stays take 1 (the clip the
+                                            // recording started on); the instance's take list
+                                            // overrides it with whichever take is active. MIDI takes
+                                            // are beats-domain and each spans one cycle region.
+                                            clip.set_content_duration(ClipDuration::Beats(loop_len_beats));
+                                            clip.name = format!("Cycle recording ({} takes)", clip_ids.len());
+                                        }
+
+                                        // Anchor to the region and select the most recent take.
+                                        // timeline_duration stays None on purpose — pinning it would
+                                        // make a later tempo change loop the take's content to fill
+                                        // the span instead of letting it drift naturally.
+                                        if let Some(AnyLayer::Audio(al)) = doc.get_layer_mut(&layer_id) {
+                                            if let Some(inst) = al.clip_instances.iter_mut().find(|ci| ci.clip_id == doc_clip_id) {
+                                                inst.timeline_start = loop_start;
+                                                inst.timeline_duration = None;
+                                                inst.trim_start = daw_backend::ContentTime::ZERO;
+                                                inst.trim_end = Some(daw_backend::ContentTime(loop_len_beats.beats_to_f64()));
+                                                inst.takes = clip_ids.iter().enumerate().map(|(i, &mid)| {
+                                                    lightningbeam_core::clip::AudioTake {
+                                                        name: format!("Take {}", i + 1),
+                                                        content: lightningbeam_core::clip::TakeContent::Midi { midi_clip_id: mid },
+                                                    }
+                                                }).collect();
+                                                inst.active_take = Some(last_take);
+                                                inst.recorded_loop_beats = Some(loop_len_beats);
+                                            }
+                                        }
+                                    }
+
+                                    // Commit the whole cycle-record session as ONE undoable action.
+                                    // The backend instance was mapped during MidiRecordingProgress and
+                                    // the engine already repointed it at the active take.
+                                    let instance = self.action_executor.document()
+                                        .get_layer(&layer_id)
+                                        .and_then(|l| if let AnyLayer::Audio(al) = l {
+                                            al.clip_instances.iter().find(|ci| ci.clip_id == doc_clip_id).cloned()
+                                        } else { None });
+                                    if let Some(instance) = instance {
+                                        match (self.layer_to_track_map.get(&layer_id).copied(),
+                                               self.clip_instance_to_backend_map.get(&instance.id).copied()) {
+                                            (Some(tid), Some(backend_id)) => {
+                                                let action = lightningbeam_core::actions::AddClipInstanceAction::already_applied(
+                                                    layer_id, instance, tid, backend_id,
+                                                );
+                                                self.action_executor.push_applied(Box::new(action));
+                                            }
+                                            _ => self.media_modified = true,
+                                        }
+                                    }
+                                }
+                            }
+
+                            // Clear recording state, same as the single-clip MIDI path.
+                            if let Some(&layer_id) = self.track_to_layer_map.get(&track_id) {
+                                self.recording_layer_ids.retain(|id| *id != layer_id);
+                                self.recording_clips.remove(&layer_id);
+                            }
+                            if self.recording_layer_ids.is_empty() {
+                                self.is_recording = false;
+                                self.recording_clips.clear();
+                            }
+                            ctx.request_repaint();
+                        }
                         AudioEvent::MidiRecordingStopped(track_id, clip_id, note_count) => {
                             println!("🎹 MIDI recording stopped: track={:?}, clip_id={}, {} notes",
                                      track_id, clip_id, note_count);
@@ -6705,7 +7149,7 @@ impl eframe::App for EditorApp {
                                             .map(|(id, _)| id);
                                         if let Some(doc_clip_id) = doc_clip_id {
                                             if let Some(clip) = self.action_executor.document_mut().audio_clips.get_mut(&doc_clip_id) {
-                                                clip.set_content_duration(ClipDuration::Beats(Beats(midi_clip_data.duration)));
+                                                clip.set_content_duration(ClipDuration::Beats(midi_clip_data.duration));
                                                 clip.name = format!("MIDI Recording {}", clip_id);
                                             }
                                         }
@@ -6833,6 +7277,20 @@ impl eframe::App for EditorApp {
 
         }
 
+        // Cycle takes that landed on an existing take folder. Deferred out of the event loop above,
+        // which holds a borrow on the event queue and so can't call a `&mut self` method.
+        for req in std::mem::take(&mut self.pending_take_appends) {
+            self.append_cycle_takes(
+                req.layer_id,
+                req.recording_instance_id,
+                req.recording_clip_id,
+                req.recording_backend_id,
+                req.loop_start,
+                req.loop_len,
+                req.takes,
+            );
+        }
+
         // Update input monitoring based on active layer (only send command when changed)
         {
             let should_monitor = self.audio_controller.is_some() && self.active_layer_id.map_or(false, |layer_id| {
@@ -7027,6 +7485,11 @@ impl eframe::App for EditorApp {
             if result.buffer_size_changed {
                 println!("⚠️  Audio buffer size will be applied on next app restart");
             }
+            // Cycle MIDI mode takes effect immediately — no restart needed, unlike the buffer size.
+            if let Some(ref controller_arc) = self.audio_controller {
+                let mut controller = controller_arc.lock().unwrap();
+                controller.set_cycle_midi_separate_takes(self.config.cycle_midi_separate_takes);
+            }
             // Apply new keybindings if changed
             if let Some(new_keymap) = result.new_keymap {
                 self.keymap = new_keymap;

lightningbeam-ui/lightningbeam-editor/src/mobile/icons.rs

@@ -42,6 +42,8 @@ pub const GRIP_HORIZONTAL: &str = "\u{e0ea}";
 pub const CHEVRONS_UP: &str = "\u{e074}";
 pub const PLAY: &str = "\u{e13c}";
 pub const PAUSE: &str = "\u{e12e}";
+pub const REPEAT: &str = "\u{e146}"; // cycle / loop region toggle
+pub const TRASH: &str = "\u{e18d}"; // delete a take
 pub const SETTINGS: &str = "\u{e154}";
 pub const SEARCH: &str = "\u{e151}";
 pub const PLUS: &str = "\u{e13d}";

lightningbeam-ui/lightningbeam-editor/src/panes/asset_library.rs

@@ -7,7 +7,7 @@
 //! - Image Assets (static images)
 
 use eframe::egui;
-use lightningbeam_core::clip::{AudioClipType, VectorClip};
+use lightningbeam_core::clip::{ResolvedContent, VectorClip};
 use lightningbeam_core::document::Document;
 use lightningbeam_core::layer::AnyLayer;
 use std::collections::{HashMap, HashSet};
@@ -918,11 +918,11 @@ impl AssetLibraryPane {
                 continue;
             }
 
-            let (extra_info, drag_clip_type) = match &clip.clip_type {
+            let (extra_info, drag_clip_type) = match &clip.resolve() {
-                AudioClipType::Sampled { .. } => ("Sampled".to_string(), DragClipType::AudioSampled),
+                ResolvedContent::Audio { .. } => ("Sampled".to_string(), DragClipType::AudioSampled),
-                AudioClipType::Midi { .. } => ("MIDI".to_string(), DragClipType::AudioMidi),
+                ResolvedContent::Midi { .. } => ("MIDI".to_string(), DragClipType::AudioMidi),
-                AudioClipType::Recording => {
+                ResolvedContent::Recording => {
-                    // Skip recording-in-progress clips from asset library
+                    // Skip recording-in-progress clips (and empty take folders) from asset library
                     continue;
                 }
             };
@@ -1118,15 +1118,15 @@ impl AssetLibraryPane {
 
                 for (id, clip) in &document.audio_clips {
                     if !linked_audio_ids.contains(id) && clip.folder_id == current_folder {
-                        let (extra_info, drag_clip_type) = match &clip.clip_type {
+                        let (extra_info, drag_clip_type) = match &clip.resolve() {
-                            AudioClipType::Sampled { .. } => {
+                            ResolvedContent::Audio { .. } => {
                                 ("Sampled".to_string(), DragClipType::AudioSampled)
                             }
-                            AudioClipType::Midi { .. } => {
+                            ResolvedContent::Midi { .. } => {
                                 ("MIDI".to_string(), DragClipType::AudioMidi)
                             }
-                            AudioClipType::Recording => {
+                            ResolvedContent::Recording => {
-                                // Skip recording-in-progress clips
+                                // Skip recording-in-progress clips (and empty take folders)
                                 continue;
                             }
                         };
@@ -1765,7 +1765,7 @@ impl AssetLibraryPane {
             let prefetched_waveform: Option<Vec<(f32, f32)>> =
                 if asset_category == AssetCategory::Audio && !self.thumbnail_cache.has(&asset_id) {
                     if let Some(clip) = document.audio_clips.get(&asset_id) {
-                        if let AudioClipType::Sampled { audio_pool_index } = &clip.clip_type {
+                        if let Some(audio_pool_index) = clip.audio_pool_index().as_ref() {
                             shared.raw_audio_cache.get(audio_pool_index)
                                 .map(|raw| peaks_from_raw_audio(raw, THUMBNAIL_SIZE as usize))
                         } else {
@@ -1790,8 +1790,8 @@ impl AssetLibraryPane {
                     AssetCategory::Audio => {
                         if let Some(clip) = document.audio_clips.get(&asset_id) {
                             let bg_color = egui::Color32::from_rgba_unmultiplied(40, 40, 40, 200);
-                            match &clip.clip_type {
+                            match &clip.resolve() {
-                                AudioClipType::Sampled { .. } => {
+                                ResolvedContent::Audio { .. } => {
                                     let wave_color = egui::Color32::from_rgb(100, 200, 100);
                                     if let Some(ref peaks) = prefetched_waveform {
                                         Some(generate_waveform_thumbnail(peaks, bg_color, wave_color))
@@ -1799,7 +1799,7 @@ impl AssetLibraryPane {
                                         Some(generate_placeholder_thumbnail(AssetCategory::Audio, 200))
                                     }
                                 }
-                                AudioClipType::Midi { midi_clip_id } => {
+                                ResolvedContent::Midi { midi_clip_id } => {
                                     let note_color = egui::Color32::from_rgb(100, 200, 100);
                                     if let Some(events) = shared.midi_event_cache.get(midi_clip_id) {
                                         Some(generate_midi_thumbnail(events, clip.content_duration().native(), bg_color, note_color))
@@ -1807,7 +1807,7 @@ impl AssetLibraryPane {
                                         Some(generate_placeholder_thumbnail(AssetCategory::Audio, 200))
                                     }
                                 }
-                                AudioClipType::Recording => {
+                                ResolvedContent::Recording => {
                                     // Recording in progress - show placeholder
                                     Some(generate_placeholder_thumbnail(AssetCategory::Audio, 200))
                                 }
@@ -2344,8 +2344,8 @@ impl AssetLibraryPane {
                 AssetCategory::Audio => {
                     if let Some(clip) = document.audio_clips.get(&asset_id) {
                         let bg_color = egui::Color32::from_rgba_unmultiplied(40, 40, 40, 200);
-                        match &clip.clip_type {
+                        match &clip.resolve() {
-                            AudioClipType::Sampled { audio_pool_index } => {
+                            ResolvedContent::Audio { audio_pool_index } => {
                                 let wave_color = egui::Color32::from_rgb(100, 200, 100);
                                 let waveform: Option<Vec<(f32, f32)>> = shared.raw_audio_cache.get(audio_pool_index)
                                     .map(|raw| peaks_from_raw_audio(raw, THUMBNAIL_SIZE as usize));
@@ -2355,7 +2355,7 @@ impl AssetLibraryPane {
                                     Some(generate_placeholder_thumbnail(AssetCategory::Audio, 200))
                                 }
                             }
-                            AudioClipType::Midi { midi_clip_id } => {
+                            ResolvedContent::Midi { midi_clip_id } => {
                                 let note_color = egui::Color32::from_rgb(100, 200, 100);
                                 if let Some(events) = shared.midi_event_cache.get(midi_clip_id) {
                                     Some(generate_midi_thumbnail(events, clip.content_duration().native(), bg_color, note_color))
@@ -2363,7 +2363,7 @@ impl AssetLibraryPane {
                                     Some(generate_placeholder_thumbnail(AssetCategory::Audio, 200))
                                 }
                             }
-                            AudioClipType::Recording => {
+                            ResolvedContent::Recording => {
                                 Some(generate_placeholder_thumbnail(AssetCategory::Audio, 200))
                             }
                         }
@@ -2481,8 +2481,8 @@ impl AssetLibraryPane {
                 AssetCategory::Audio => {
                     if let Some(clip) = document.audio_clips.get(&asset_id) {
                         let bg_color = egui::Color32::from_rgba_unmultiplied(40, 40, 40, 200);
-                        match &clip.clip_type {
+                        match &clip.resolve() {
-                            AudioClipType::Sampled { audio_pool_index } => {
+                            ResolvedContent::Audio { audio_pool_index } => {
                                 let wave_color = egui::Color32::from_rgb(100, 200, 100);
                                 let waveform: Option<Vec<(f32, f32)>> = shared.raw_audio_cache.get(audio_pool_index)
                                     .map(|raw| peaks_from_raw_audio(raw, THUMBNAIL_SIZE as usize));
@@ -2492,7 +2492,7 @@ impl AssetLibraryPane {
                                     Some(generate_placeholder_thumbnail(AssetCategory::Audio, 200))
                                 }
                             }
-                            AudioClipType::Midi { midi_clip_id } => {
+                            ResolvedContent::Midi { midi_clip_id } => {
                                 let note_color = egui::Color32::from_rgb(100, 200, 100);
                                 if let Some(events) = shared.midi_event_cache.get(midi_clip_id) {
                                     Some(generate_midi_thumbnail(events, clip.content_duration().native(), bg_color, note_color))
@@ -2500,7 +2500,7 @@ impl AssetLibraryPane {
                                     Some(generate_placeholder_thumbnail(AssetCategory::Audio, 200))
                                 }
                             }
-                            AudioClipType::Recording => {
+                            ResolvedContent::Recording => {
                                 Some(generate_placeholder_thumbnail(AssetCategory::Audio, 200))
                             }
                         }
@@ -2802,7 +2802,7 @@ impl AssetLibraryPane {
                         let prefetched_waveform: Option<Vec<(f32, f32)>> =
                             if asset_category == AssetCategory::Audio && !self.thumbnail_cache.has(&asset_id) {
                                 if let Some(clip) = document.audio_clips.get(&asset_id) {
-                                    if let AudioClipType::Sampled { audio_pool_index } = &clip.clip_type {
+                                    if let Some(audio_pool_index) = clip.audio_pool_index().as_ref() {
                                         let waveform: Option<Vec<(f32, f32)>> = shared.raw_audio_cache.get(audio_pool_index)
                                             .map(|raw| peaks_from_raw_audio(raw, THUMBNAIL_SIZE as usize));
                                         if waveform.is_some() {
@@ -2842,8 +2842,8 @@ impl AssetLibraryPane {
                                     // Check if it's sampled or MIDI
                                     if let Some(clip) = document.audio_clips.get(&asset_id) {
                                         let bg_color = egui::Color32::from_rgba_unmultiplied(40, 40, 40, 200);
-                                        match &clip.clip_type {
+                                        match &clip.resolve() {
-                                            AudioClipType::Sampled { .. } => {
+                                            ResolvedContent::Audio { .. } => {
                                                 let wave_color = egui::Color32::from_rgb(100, 200, 100);
                                                 if let Some(ref peaks) = prefetched_waveform {
                                                     println!("✅ Generating waveform thumbnail with {} peaks for asset {}", peaks.len(), asset_id);
@@ -2853,7 +2853,7 @@ impl AssetLibraryPane {
                                                     Some(generate_placeholder_thumbnail(AssetCategory::Audio, 200))
                                                 }
                                             }
-                                            AudioClipType::Midi { midi_clip_id } => {
+                                            ResolvedContent::Midi { midi_clip_id } => {
                                                 let bg_color = egui::Color32::from_rgba_unmultiplied(40, 40, 40, 200);
                                                 let note_color = egui::Color32::from_rgb(100, 200, 100);
 
@@ -2863,7 +2863,7 @@ impl AssetLibraryPane {
                                                     Some(generate_placeholder_thumbnail(AssetCategory::Audio, 200))
                                                 }
                                             }
-                                            AudioClipType::Recording => {
+                                            ResolvedContent::Recording => {
                                                 Some(generate_placeholder_thumbnail(AssetCategory::Audio, 200))
                                             }
                                         }
@@ -3187,7 +3187,7 @@ impl PaneRenderer for AssetLibraryPane {
             println!("🎨 [ASSET_LIB] Checking for thumbnails to invalidate (pools: {:?})", shared.audio_pools_with_new_waveforms);
             let mut invalidated_any = false;
             for (asset_id, clip) in &document_arc.audio_clips {
-                if let lightningbeam_core::clip::AudioClipType::Sampled { audio_pool_index } = &clip.clip_type {
+                if let Some(audio_pool_index) = clip.audio_pool_index().as_ref() {
                     if shared.audio_pools_with_new_waveforms.contains(audio_pool_index) {
                         println!("❌ [ASSET_LIB] Invalidating thumbnail for asset {} (pool {})", asset_id, audio_pool_index);
                         self.thumbnail_cache.invalidate(asset_id);

lightningbeam-ui/lightningbeam-editor/src/panes/infopanel.rs

@@ -1612,8 +1612,12 @@ impl InfopanelPane {
                                 ui.label(format!("{:.2}s", document.tempo_map().beats_to_seconds(ci.effective_start()).seconds_to_f64()));
                             });
 
-                            let clip_dur = document.get_clip_duration(&ci.clip_id)
+                            let clip_dur = document.clip_trim_duration(&ci.clip_id)
-                                .unwrap_or_else(|| daw_backend::Seconds(ci.trim_end.unwrap_or(1.0) - ci.trim_start));
+                                .unwrap_or_else(|| lightningbeam_core::clip::ClipDuration::Seconds(
+                                    daw_backend::Seconds(
+                                        (ci.trim_end.unwrap_or(daw_backend::ContentTime(1.0)) - ci.trim_start).raw(),
+                                    ),
+                                ));
                             let total_dur = ci.total_duration(clip_dur, document.tempo_map());
                             let total_dur_secs = (document.tempo_map().beats_to_seconds(ci.effective_start() + total_dur)
                                 - document.tempo_map().beats_to_seconds(ci.effective_start())).seconds_to_f64();
@@ -1622,10 +1626,16 @@ impl InfopanelPane {
                                 ui.label(format!("{:.2}s", total_dur_secs));
                             });
 
-                            if ci.trim_start > 0.0 {
+                            if ci.trim_start > daw_backend::ContentTime::ZERO {
                                 ui.horizontal(|ui| {
                                     ui.label("Trim Start:");
-                                    ui.label(format!("{:.2}s", ci.trim_start));
+                                    // Content time in the clip's own domain: seconds for sampled
+                                    // audio/video/vector, beats for MIDI. Label it accordingly.
+                                    let unit = match clip_dur {
+                                        lightningbeam_core::clip::ClipDuration::Beats(_) => "beats",
+                                        lightningbeam_core::clip::ClipDuration::Seconds(_) => "s",
+                                    };
+                                    ui.label(format!("{:.2}{}", ci.trim_start.raw(), unit));
                                 });
                             }
 

lightningbeam-ui/lightningbeam-editor/src/panes/piano_roll.rs

@@ -465,9 +465,13 @@ impl PianoRollPane {
             if let Some(AnyLayer::Audio(audio_layer)) = document.get_layer(&layer_id) {
                 for instance in &audio_layer.clip_instances {
                     if let Some(clip) = document.audio_clips.get(&instance.clip_id) {
-                        if let AudioClipType::Midi { midi_clip_id } = clip.clip_type {
+                        // Resolve through the instance's active take, so a MIDI take folder edits
-                            let duration = instance.effective_duration(clip.content_duration().to_seconds(document.tempo_map()), document.tempo_map());
+                        // whichever take it's actually playing.
-                            clip_data.push((midi_clip_id, instance.timeline_start.beats_to_f64(), instance.trim_start, duration.beats_to_f64(), instance.id));
+                        if let Some(midi_clip_id) = instance.resolved_midi_clip_id(clip) {
+                            let duration = instance.effective_duration(clip.content_duration(), document.tempo_map());
+                            // A MIDI clip's content time IS beats, which is what the piano roll's
+                            // x-axis uses.
+                            clip_data.push((midi_clip_id, instance.timeline_start.beats_to_f64(), instance.trim_start.raw(), duration.beats_to_f64(), instance.id));
                         }
                     }
                 }
@@ -2463,7 +2467,8 @@ impl PianoRollPane {
                         });
                         // Get sample rate from raw_audio_cache
                         if let Some((_samples, sr, _ch)) = shared.raw_audio_cache.get(&audio_pool_index) {
-                            clip_infos.push((audio_pool_index, instance.timeline_start.beats_to_f64(), instance.trim_start, duration.beats_to_f64(), *sr));
+                            // A sampled clip's content time is seconds.
+                            clip_infos.push((audio_pool_index, instance.timeline_start.beats_to_f64(), instance.trim_start.raw(), duration.beats_to_f64(), *sr));
                         }
                     }
                 }

lightningbeam-ui/lightningbeam-editor/src/panes/stage.rs

@@ -6,7 +6,7 @@
 use eframe::egui;
 use daw_backend::Seconds;
 use lightningbeam_core::action::Action;
-use lightningbeam_core::clip::ClipInstance;
+use lightningbeam_core::clip::{ClipDuration, ClipInstance};
 use lightningbeam_core::gpu::{BufferPool, BufferFormat, BufferSpec, Compositor, EffectProcessor, SrgbToLinearConverter};
 use lightningbeam_core::layer::{AnyLayer, AudioLayer};
 use lightningbeam_core::renderer::RenderedLayerType;
@@ -1854,7 +1854,10 @@ impl egui_wgpu::CallbackTrait for VelloCallback {
                             // For now, create a simple effect instance with default parameters
                             let tempo_map = self.ctx.document.tempo_map();
                             let effect_end_beats = effect_instance.timeline_start
-                                + effect_instance.effective_duration(Seconds(lightningbeam_core::effect::EFFECT_DURATION), tempo_map);
+                                + effect_instance.effective_duration(
+            ClipDuration::Seconds(Seconds(lightningbeam_core::effect::EFFECT_DURATION)),
+            tempo_map,
+        );
                             let effect_inst = lightningbeam_core::effect::EffectInstance::new(
                                 effect_def,
                                 tempo_map.beats_to_seconds(effect_instance.timeline_start).seconds_to_f64(),
@@ -2209,7 +2212,7 @@ impl egui_wgpu::CallbackTrait for VelloCallback {
 
                                 // Calculate clip bounds for preview
                                 let start_secs = self.ctx.document.tempo_map().beats_to_seconds(clip_inst.timeline_start).seconds_to_f64();
-                                let clip_time = ((self.ctx.playback_time - start_secs) * clip_inst.playback_speed) + clip_inst.trim_start;
+                                let clip_time = ((self.ctx.playback_time - start_secs) * clip_inst.playback_speed) + clip_inst.trim_start.raw();
                                 let content_bounds = if let Some(vector_clip) = self.ctx.document.get_vector_clip(&clip_inst.clip_id) {
                                     vector_clip.calculate_content_bounds(&self.ctx.document, clip_time)
                                 } else if let Some(video_clip) = self.ctx.document.get_video_clip(&clip_inst.clip_id) {
@@ -2299,7 +2302,9 @@ impl egui_wgpu::CallbackTrait for VelloCallback {
                         for &clip_id in self.ctx.selection.clip_instances() {
                             if let Some(clip_instance) = vector_layer.clip_instances.iter().find(|ci| ci.id == clip_id) {
                                 // Skip clip instances not active at current time (compare in seconds).
-                                let clip_dur = self.ctx.document.get_clip_duration(&clip_instance.clip_id).unwrap_or(Seconds::ZERO);
+                                let clip_dur = ClipDuration::Seconds(
+                                    self.ctx.document.get_clip_duration(&clip_instance.clip_id).unwrap_or(Seconds::ZERO),
+                                );
                                 let tempo_map = self.ctx.document.tempo_map();
                                 let start_secs = tempo_map.beats_to_seconds(clip_instance.timeline_start).seconds_to_f64();
                                 let instance_end = tempo_map.beats_to_seconds(
@@ -2310,7 +2315,7 @@ impl egui_wgpu::CallbackTrait for VelloCallback {
                                 }
 
                                 // Calculate clip-local time
-                                let clip_time = ((self.ctx.playback_time - start_secs) * clip_instance.playback_speed) + clip_instance.trim_start;
+                                let clip_time = ((self.ctx.playback_time - start_secs) * clip_instance.playback_speed) + clip_instance.trim_start.raw();
 
                                 // Get dynamic clip bounds from content at current time
                                 let bbox = if let Some(vector_clip) = self.ctx.document.get_vector_clip(&clip_instance.clip_id) {
@@ -2680,7 +2685,9 @@ impl egui_wgpu::CallbackTrait for VelloCallback {
 
                         // Find clip instance visible at playback time
                         let visible_clip = video_layer.clip_instances.iter().find(|inst| {
-                            let clip_duration = self.ctx.document.get_clip_duration(&inst.clip_id).unwrap_or(Seconds::ZERO);
+                            let clip_duration = ClipDuration::Seconds(
+                                self.ctx.document.get_clip_duration(&inst.clip_id).unwrap_or(Seconds::ZERO),
+                            );
                             let tempo_map = self.ctx.document.tempo_map();
                             let start_secs = tempo_map.beats_to_seconds(inst.timeline_start).seconds_to_f64();
                             let end_secs = tempo_map.beats_to_seconds(inst.timeline_start + inst.effective_duration(clip_duration, tempo_map)).seconds_to_f64();
@@ -10142,7 +10149,7 @@ impl StagePane {
                     if let Some(clip_instance) = vector_layer.clip_instances.iter().find(|ci| ci.id == clip_id) {
                         // Calculate clip-local time
                         let start_secs = shared.action_executor.document().tempo_map().beats_to_seconds(clip_instance.timeline_start).seconds_to_f64();
-                        let clip_time = ((*shared.playback_time - start_secs) * clip_instance.playback_speed) + clip_instance.trim_start;
+                        let clip_time = ((*shared.playback_time - start_secs) * clip_instance.playback_speed) + clip_instance.trim_start.raw();
 
                         // Get dynamic clip bounds from content at current time
                         use vello::kurbo::Rect as KurboRect;
@@ -10343,7 +10350,7 @@ impl StagePane {
                 if let Some(clip_instance) = vector_layer.clip_instances.iter().find(|ci| ci.id == object_id) {
                     // Calculate clip-local time
                     let start_secs = shared.action_executor.document().tempo_map().beats_to_seconds(clip_instance.timeline_start).seconds_to_f64();
-                    let clip_time = ((*shared.playback_time - start_secs) * clip_instance.playback_speed) + clip_instance.trim_start;
+                    let clip_time = ((*shared.playback_time - start_secs) * clip_instance.playback_speed) + clip_instance.trim_start.raw();
 
                     // Get dynamic clip bounds from content at current time
                     let local_bbox = if let Some(vector_clip) = shared.action_executor.document().get_vector_clip(&clip_instance.clip_id) {
@@ -11059,7 +11066,9 @@ impl StagePane {
             let document = shared.action_executor.document();
             if let Some(AnyLayer::Video(video_layer)) = document.get_layer(layer_id) {
                 video_layer.clip_instances.iter().find(|inst| {
-                    let clip_duration = document.get_clip_duration(&inst.clip_id).unwrap_or(Seconds::ZERO);
+                    let clip_duration = ClipDuration::Seconds(
+                        document.get_clip_duration(&inst.clip_id).unwrap_or(Seconds::ZERO),
+                    );
                     let tempo_map = document.tempo_map();
                     let start_secs = tempo_map.beats_to_seconds(inst.timeline_start).seconds_to_f64();
                     let end_secs = tempo_map.beats_to_seconds(inst.timeline_start + inst.effective_duration(clip_duration, tempo_map)).seconds_to_f64();

lightningbeam-ui/lightningbeam-editor/src/preferences/dialog.rs

@@ -55,6 +55,7 @@ struct PreferencesState {
     file_height: u32,
     scroll_speed: f64,
     audio_buffer_size: u32,
+    cycle_midi_separate_takes: bool,
     reopen_last_session: bool,
     restore_layout_from_file: bool,
     debug: bool,
@@ -72,6 +73,7 @@ impl From<(&AppConfig, &Theme)> for PreferencesState {
             file_height: config.file_height,
             scroll_speed: config.scroll_speed,
             audio_buffer_size: config.audio_buffer_size,
+            cycle_midi_separate_takes: config.cycle_midi_separate_takes,
             reopen_last_session: config.reopen_last_session,
             restore_layout_from_file: config.restore_layout_from_file,
             debug: config.debug,
@@ -91,6 +93,7 @@ impl Default for PreferencesState {
             file_height: 600,
             scroll_speed: 1.0,
             audio_buffer_size: 256,
+            cycle_midi_separate_takes: false,
             reopen_last_session: false,
             restore_layout_from_file: true,
             debug: false,
@@ -543,6 +546,39 @@ impl PreferencesDialog {
                 });
 
                 ui.label("Requires app restart to take effect");
+
+                ui.separator();
+
+                ui.horizontal(|ui| {
+                    ui.label("Cycle MIDI recording:");
+
+                    egui::ComboBox::from_id_salt("cycle_midi_mode")
+                        .selected_text(if self.working_prefs.cycle_midi_separate_takes {
+                            "Separate takes"
+                        } else {
+                            "Merge"
+                        })
+                        .show_ui(ui, |ui| {
+                            ui.selectable_value(
+                                &mut self.working_prefs.cycle_midi_separate_takes,
+                                false,
+                                "Merge",
+                            )
+                            .on_hover_text(
+                                "Every pass overdubs into one clip, and earlier passes play back as \
+                                 you record so you can layer against them.",
+                            );
+                            ui.selectable_value(
+                                &mut self.working_prefs.cycle_midi_separate_takes,
+                                true,
+                                "Separate takes",
+                            )
+                            .on_hover_text(
+                                "Each pass becomes its own take in a take folder, as audio always \
+                                 does. Earlier passes stay silent — they're alternatives, not layers.",
+                            );
+                        });
+                });
             });
     }
 
@@ -641,6 +677,7 @@ impl PreferencesDialog {
         temp_config.file_height = self.working_prefs.file_height;
         temp_config.scroll_speed = self.working_prefs.scroll_speed;
         temp_config.audio_buffer_size = self.working_prefs.audio_buffer_size;
+        temp_config.cycle_midi_separate_takes = self.working_prefs.cycle_midi_separate_takes;
         temp_config.reopen_last_session = self.working_prefs.reopen_last_session;
         temp_config.restore_layout_from_file = self.working_prefs.restore_layout_from_file;
         temp_config.debug = self.working_prefs.debug;
@@ -675,6 +712,7 @@ impl PreferencesDialog {
         config.file_height = self.working_prefs.file_height;
         config.scroll_speed = self.working_prefs.scroll_speed;
         config.audio_buffer_size = self.working_prefs.audio_buffer_size;
+        config.cycle_midi_separate_takes = self.working_prefs.cycle_midi_separate_takes;
         config.reopen_last_session = self.working_prefs.reopen_last_session;
         config.restore_layout_from_file = self.working_prefs.restore_layout_from_file;
         config.debug = self.working_prefs.debug;