diff --git a/crates/app/src/model.rs b/crates/app/src/model.rs
index 343bc02a..660e0cff 100644
--- a/crates/app/src/model.rs
+++ b/crates/app/src/model.rs
@@ -2,7 +2,10 @@ use crate::*;
 
 mod dialog;    pub use self::dialog::*;
 mod editor;    pub use self::editor::*;
+mod pool;      pub use self::pool::*;
 mod selection; pub use self::selection::*;
+mod track;     pub use self::track::*;
+mod scene;     pub use self::scene::*;
 
 #[derive(Default, Debug)]
 pub struct Tek {
@@ -456,426 +459,3 @@ has_editor!(|self: Tek|{
     editor_h = 15;
     is_editing = self.editing.load(Relaxed);
 });
-
-pub trait HasScenes: HasSelection + HasEditor + Send + Sync {
-    fn scenes (&self) -> &Vec<Scene>;
-    fn scenes_mut (&mut self) -> &mut Vec<Scene>;
-    fn scene_longest (&self) -> usize {
-        self.scenes().iter().map(|s|s.name.len()).fold(0, usize::max)
-    }
-    fn scene (&self) -> Option<&Scene> {
-        self.selected().scene().and_then(|s|self.scenes().get(s))
-    }
-    fn scene_mut (&mut self) -> Option<&mut Scene> {
-        self.selected().scene().and_then(|s|self.scenes_mut().get_mut(s))
-    }
-    fn scene_del (&mut self, index: usize) {
-        self.selected().scene().and_then(|s|Some(self.scenes_mut().remove(index)));
-    }
-    /// Set the color of a scene, returning the previous one.
-    fn scene_set_color (&mut self, index: usize, color: ItemTheme) -> ItemTheme {
-        let scenes = self.scenes_mut();
-        let old = scenes[index].color;
-        scenes[index].color = color;
-        old
-    }
-    /// Generate the default name for a new scene
-    fn scene_default_name (&self) -> Arc<str> {
-        format!("Sc{:3>}", self.scenes().len() + 1).into()
-    }
-}
-
-#[derive(Debug, Default)] pub struct Scene {
-    /// Name of scene
-    pub name:  Arc<str>,
-    /// Clips in scene, one per track
-    pub clips: Vec<Option<Arc<RwLock<MidiClip>>>>,
-    /// Identifying color of scene
-    pub color: ItemTheme,
-}
-
-impl Scene {
-    /// Returns the pulse length of the longest clip in the scene
-    pub fn pulses (&self) -> usize {
-        self.clips.iter().fold(0, |a, p|{
-            a.max(p.as_ref().map(|q|q.read().unwrap().length).unwrap_or(0))
-        })
-    }
-    /// Returns true if all clips in the scene are
-    /// currently playing on the given collection of tracks.
-    pub fn is_playing (&self, tracks: &[Track]) -> bool {
-        self.clips.iter().any(|clip|clip.is_some()) && self.clips.iter().enumerate()
-            .all(|(track_index, clip)|match clip {
-                Some(c) => tracks
-                    .get(track_index)
-                    .map(|track|{
-                        if let Some((_, Some(clip))) = track.player().play_clip() {
-                            *clip.read().unwrap() == *c.read().unwrap()
-                        } else {
-                            false
-                        }
-                    })
-                    .unwrap_or(false),
-                None => true
-            })
-    }
-    pub fn clip (&self, index: usize) -> Option<&Arc<RwLock<MidiClip>>> {
-        match self.clips.get(index) { Some(Some(clip)) => Some(clip), _ => None }
-    }
-}
-
-impl HasScenes for Tek {
-    fn scenes (&self) -> &Vec<Scene> { &self.scenes }
-    fn scenes_mut (&mut self) -> &mut Vec<Scene> { &mut self.scenes }
-}
-
-pub trait HasTracks: HasSelection + HasClock + HasJack + HasEditor + Send + Sync {
-    fn midi_ins (&self) -> &Vec<JackMidiIn>;
-    fn midi_outs (&self) -> &Vec<JackMidiOut>;
-    fn tracks (&self) -> &Vec<Track>;
-    fn tracks_mut (&mut self) -> &mut Vec<Track>;
-    fn track_longest (&self) -> usize {
-        self.tracks().iter().map(|s|s.name.len()).fold(0, usize::max)
-    }
-    const WIDTH_OFFSET: usize = 1;
-    fn track (&self) -> Option<&Track> {
-        self.selected().track().and_then(|s|self.tracks().get(s))
-    }
-    fn track_mut (&mut self) -> Option<&mut Track> {
-        self.selected().track().and_then(|s|self.tracks_mut().get_mut(s))
-    }
-    /// Set the color of a track
-    fn track_set_color (&mut self, index: usize, color: ItemTheme) -> ItemTheme {
-        let tracks = self.tracks_mut();
-        let old = tracks[index].color;
-        tracks[index].color = color;
-        old
-    }
-    /// Toggle track recording
-    fn track_toggle_record (&mut self) {
-        if let Some(t) = self.selected().track() {
-            let tracks = self.tracks_mut();
-            tracks[t-1].player.recording = !tracks[t-1].player.recording;
-        }
-    }
-    /// Toggle track monitoring
-    fn track_toggle_monitor (&mut self) {
-        if let Some(t) = self.selected().track() {
-            let tracks = self.tracks_mut();
-            tracks[t-1].player.monitoring = !tracks[t-1].player.monitoring;
-        }
-    }
-}
-
-#[derive(Debug, Default)] pub struct Track {
-    /// Name of track
-    pub name:       Arc<str>,
-    /// Preferred width of track column
-    pub width:      usize,
-    /// Identifying color of track
-    pub color:      ItemTheme,
-    /// MIDI player state
-    pub player:     MidiPlayer,
-    /// Device chain
-    pub devices:    Vec<Device>,
-    /// Inputs of 1st device
-    pub audio_ins:  Vec<JackAudioIn>,
-    /// Outputs of last device
-    pub audio_outs: Vec<JackAudioOut>,
-}
-
-has_clock!(|self: Track|self.player.clock);
-
-has_player!(|self: Track|self.player);
-
-impl Track {
-    pub const MIN_WIDTH: usize = 9;
-    /// Create a new track containing a sequencer.
-    pub fn new_sequencer () -> Self {
-        let mut track = Self::default();
-        track.devices.push(Device::Sequencer(MidiPlayer::default()));
-        track
-    }
-    /// Create a new track containing a sequencer and sampler.
-    pub fn new_groovebox (
-        jack:       &Jack,
-        midi_from:  &[PortConnect],
-        audio_from: &[&[PortConnect];2],
-        audio_to:   &[&[PortConnect];2],
-    ) -> Usually<Self> {
-        let mut track = Self::new_sequencer();
-        track.devices.push(Device::Sampler(
-            Sampler::new(jack, &"sampler", midi_from, audio_from, audio_to)?
-        ));
-        Ok(track)
-    }
-    /// Create a new track containing a sampler.
-    pub fn new_sampler (
-        jack:       &Jack,
-        midi_from:  &[PortConnect],
-        audio_from: &[&[PortConnect];2],
-        audio_to:   &[&[PortConnect];2],
-    ) -> Usually<Self> {
-        let mut track = Self::default();
-        track.devices.push(Device::Sampler(
-            Sampler::new(jack, &"sampler", midi_from, audio_from, audio_to)?
-        ));
-        Ok(track)
-    }
-    pub fn width_inc (&mut self) {
-        self.width += 1;
-    }
-    pub fn width_dec (&mut self) {
-        if self.width > Track::MIN_WIDTH {
-            self.width -= 1;
-        }
-    }
-    pub fn sequencer (&self, mut nth: usize) -> Option<&MidiPlayer> {
-        for device in self.devices.iter() {
-            match device {
-                Device::Sequencer(s) => if nth == 0 {
-                    return Some(s);
-                } else {
-                    nth -= 1;
-                },
-                _ => {}
-            }
-        }
-        None
-    }
-    pub fn sampler (&self, mut nth: usize) -> Option<&Sampler> {
-        for device in self.devices.iter() {
-            match device {
-                Device::Sampler(s) => if nth == 0 {
-                    return Some(s);
-                } else {
-                    nth -= 1;
-                },
-                _ => {}
-            }
-        }
-        None
-    }
-    pub fn sampler_mut (&mut self, mut nth: usize) -> Option<&mut Sampler> {
-        for device in self.devices.iter_mut() {
-            match device {
-                Device::Sampler(s) => if nth == 0 {
-                    return Some(s);
-                } else {
-                    nth -= 1;
-                },
-                _ => {}
-            }
-        }
-        None
-    }
-}
-
-impl HasTracks for Tek {
-    fn midi_ins (&self) -> &Vec<JackMidiIn> { &self.midi_ins }
-    fn midi_outs (&self) -> &Vec<JackMidiOut> { &self.midi_outs }
-    fn tracks (&self) -> &Vec<Track> { &self.tracks }
-    fn tracks_mut (&mut self) -> &mut Vec<Track> { &mut self.tracks }
-}
-
-#[derive(Debug)]
-pub struct MidiPool {
-    pub visible: bool,
-    /// Collection of clips
-    pub clips: Arc<RwLock<Vec<Arc<RwLock<MidiClip>>>>>,
-    /// Selected clip
-    pub clip: AtomicUsize,
-    /// Mode switch
-    pub mode: Option<PoolMode>,
-}
-
-impl Default for MidiPool {
-    fn default () -> Self {
-        use PoolMode::*;
-        Self {
-            visible: true,
-            clips: Arc::from(RwLock::from(vec![])),
-            clip: 0.into(),
-            mode: None,
-        }
-    }
-}
-
-has_clips!(|self: MidiPool|self.clips);
-
-has_clip!(|self: MidiPool|self.clips().get(self.clip_index()).map(|c|c.clone()));
-
-from!(|clip:&Arc<RwLock<MidiClip>>|MidiPool = {
-    let model = Self::default();
-    model.clips.write().unwrap().push(clip.clone());
-    model.clip.store(1, Relaxed);
-    model
-});
-
-impl MidiPool {
-    pub fn clip_index (&self) -> usize {
-        self.clip.load(Relaxed)
-    }
-    pub fn set_clip_index (&self, value: usize) {
-        self.clip.store(value, Relaxed);
-    }
-    pub fn mode (&self) -> &Option<PoolMode> {
-        &self.mode
-    }
-    pub fn mode_mut (&mut self) -> &mut Option<PoolMode> {
-        &mut self.mode
-    }
-    pub fn begin_clip_length (&mut self) {
-        let length = self.clips()[self.clip_index()].read().unwrap().length;
-        *self.mode_mut() = Some(PoolMode::Length(
-            self.clip_index(),
-            length,
-            ClipLengthFocus::Bar
-        ));
-    }
-    pub fn begin_clip_rename (&mut self) {
-        let name = self.clips()[self.clip_index()].read().unwrap().name.clone();
-        *self.mode_mut() = Some(PoolMode::Rename(
-            self.clip_index(),
-            name
-        ));
-    }
-    pub fn begin_import (&mut self) -> Usually<()> {
-        *self.mode_mut() = Some(PoolMode::Import(
-            self.clip_index(),
-            FileBrowser::new(None)?
-        ));
-        Ok(())
-    }
-    pub fn begin_export (&mut self) -> Usually<()> {
-        *self.mode_mut() = Some(PoolMode::Export(
-            self.clip_index(),
-            FileBrowser::new(None)?
-        ));
-        Ok(())
-    }
-    pub fn new_clip (&self) -> MidiClip {
-        MidiClip::new("Clip", true, 4 * PPQ, None, Some(ItemTheme::random()))
-    }
-    pub fn cloned_clip (&self) -> MidiClip {
-        let index    = self.clip_index();
-        let mut clip = self.clips()[index].read().unwrap().duplicate();
-        clip.color   = ItemTheme::random_near(clip.color, 0.25);
-        clip
-    }
-    pub fn add_new_clip (&self) -> (usize, Arc<RwLock<MidiClip>>) {
-        let clip = Arc::new(RwLock::new(self.new_clip()));
-        let index = {
-            let mut clips = self.clips.write().unwrap();
-            clips.push(clip.clone());
-            clips.len().saturating_sub(1)
-        };
-        self.clip.store(index, Relaxed);
-        (index, clip)
-    }
-    pub fn delete_clip (&mut self, clip: &MidiClip) -> bool {
-        let index = self.clips.read().unwrap().iter().position(|x|*x.read().unwrap()==*clip);
-        if let Some(index) = index {
-            self.clips.write().unwrap().remove(index);
-            return true
-        }
-        false
-    }
-}
-
-/// Modes for clip pool
-#[derive(Debug, Clone)]
-pub enum PoolMode {
-    /// Renaming a pattern
-    Rename(usize, Arc<str>),
-    /// Editing the length of a pattern
-    Length(usize, usize, ClipLengthFocus),
-    /// Load clip from disk
-    Import(usize, FileBrowser),
-    /// Save clip to disk
-    Export(usize, FileBrowser),
-}
-
-/// Focused field of `ClipLength`
-#[derive(Copy, Clone, Debug)]
-pub enum ClipLengthFocus {
-    /// Editing the number of bars
-    Bar,
-    /// Editing the number of beats
-    Beat,
-    /// Editing the number of ticks
-    Tick,
-}
-
-impl ClipLengthFocus {
-    pub fn next (&mut self) {
-        use ClipLengthFocus::*;
-        *self = match self { Bar => Beat, Beat => Tick, Tick => Bar, }
-    }
-    pub fn prev (&mut self) {
-        use ClipLengthFocus::*;
-        *self = match self { Bar => Tick, Beat => Bar, Tick => Beat, }
-    }
-}
-
-/// Displays and edits clip length.
-#[derive(Clone)]
-pub struct ClipLength {
-    /// Pulses per beat (quaver)
-    ppq: usize,
-    /// Beats per bar
-    bpb: usize,
-    /// Length of clip in pulses
-    pulses: usize,
-    /// Selected subdivision
-    pub focus: Option<ClipLengthFocus>,
-}
-
-impl ClipLength {
-    pub fn _new (pulses: usize, focus: Option<ClipLengthFocus>) -> Self {
-        Self { ppq: PPQ, bpb: 4, pulses, focus }
-    }
-    pub fn bars  (&self) -> usize {
-        self.pulses / (self.bpb * self.ppq)
-    }
-    pub fn beats (&self) -> usize {
-        (self.pulses % (self.bpb * self.ppq)) / self.ppq
-    }
-    pub fn ticks (&self) -> usize {
-        self.pulses % self.ppq
-    }
-    pub fn bars_string  (&self) -> Arc<str> {
-        format!("{}", self.bars()).into()
-    }
-    pub fn beats_string (&self) -> Arc<str> {
-        format!("{}", self.beats()).into()
-    }
-    pub fn ticks_string (&self) -> Arc<str> {
-        format!("{:>02}", self.ticks()).into()
-    }
-}
-
-pub type ClipPool = Vec<Arc<RwLock<MidiClip>>>;
-
-pub trait HasClips {
-    fn clips <'a> (&'a self) -> std::sync::RwLockReadGuard<'a, ClipPool>;
-    fn clips_mut <'a> (&'a self) -> std::sync::RwLockWriteGuard<'a, ClipPool>;
-    fn add_clip (&self) -> (usize, Arc<RwLock<MidiClip>>) {
-        let clip = Arc::new(RwLock::new(MidiClip::new("Clip", true, 384, None, None)));
-        self.clips_mut().push(clip.clone());
-        (self.clips().len() - 1, clip)
-    }
-}
-
-#[macro_export] macro_rules! has_clips {
-    (|$self:ident:$Struct:ident$(<$($L:lifetime),*$($T:ident$(:$U:path)?),*>)?|$cb:expr) => {
-        impl $(<$($L),*$($T $(: $U)?),*>)? HasClips for $Struct $(<$($L),*$($T),*>)? {
-            fn clips <'a> (&'a $self) -> std::sync::RwLockReadGuard<'a, ClipPool>      {
-                $cb.read().unwrap()
-            }
-            fn clips_mut <'a> (&'a $self) -> std::sync::RwLockWriteGuard<'a, ClipPool> {
-                $cb.write().unwrap()
-            }
-        }
-    }
-}
diff --git a/crates/app/src/model/pool.rs b/crates/app/src/model/pool.rs
new file mode 100644
index 00000000..5ef5e01b
--- /dev/null
+++ b/crates/app/src/model/pool.rs
@@ -0,0 +1,203 @@
+use crate::*;
+
+#[derive(Debug)]
+pub struct MidiPool {
+    pub visible: bool,
+    /// Collection of clips
+    pub clips: Arc<RwLock<Vec<Arc<RwLock<MidiClip>>>>>,
+    /// Selected clip
+    pub clip: AtomicUsize,
+    /// Mode switch
+    pub mode: Option<PoolMode>,
+}
+
+impl Default for MidiPool {
+    fn default () -> Self {
+        use PoolMode::*;
+        Self {
+            visible: true,
+            clips: Arc::from(RwLock::from(vec![])),
+            clip: 0.into(),
+            mode: None,
+        }
+    }
+}
+
+has_clips!(|self: MidiPool|self.clips);
+
+has_clip!(|self: MidiPool|self.clips().get(self.clip_index()).map(|c|c.clone()));
+
+from!(|clip:&Arc<RwLock<MidiClip>>|MidiPool = {
+    let model = Self::default();
+    model.clips.write().unwrap().push(clip.clone());
+    model.clip.store(1, Relaxed);
+    model
+});
+
+impl MidiPool {
+    pub fn clip_index (&self) -> usize {
+        self.clip.load(Relaxed)
+    }
+    pub fn set_clip_index (&self, value: usize) {
+        self.clip.store(value, Relaxed);
+    }
+    pub fn mode (&self) -> &Option<PoolMode> {
+        &self.mode
+    }
+    pub fn mode_mut (&mut self) -> &mut Option<PoolMode> {
+        &mut self.mode
+    }
+    pub fn begin_clip_length (&mut self) {
+        let length = self.clips()[self.clip_index()].read().unwrap().length;
+        *self.mode_mut() = Some(PoolMode::Length(
+            self.clip_index(),
+            length,
+            ClipLengthFocus::Bar
+        ));
+    }
+    pub fn begin_clip_rename (&mut self) {
+        let name = self.clips()[self.clip_index()].read().unwrap().name.clone();
+        *self.mode_mut() = Some(PoolMode::Rename(
+            self.clip_index(),
+            name
+        ));
+    }
+    pub fn begin_import (&mut self) -> Usually<()> {
+        *self.mode_mut() = Some(PoolMode::Import(
+            self.clip_index(),
+            FileBrowser::new(None)?
+        ));
+        Ok(())
+    }
+    pub fn begin_export (&mut self) -> Usually<()> {
+        *self.mode_mut() = Some(PoolMode::Export(
+            self.clip_index(),
+            FileBrowser::new(None)?
+        ));
+        Ok(())
+    }
+    pub fn new_clip (&self) -> MidiClip {
+        MidiClip::new("Clip", true, 4 * PPQ, None, Some(ItemTheme::random()))
+    }
+    pub fn cloned_clip (&self) -> MidiClip {
+        let index    = self.clip_index();
+        let mut clip = self.clips()[index].read().unwrap().duplicate();
+        clip.color   = ItemTheme::random_near(clip.color, 0.25);
+        clip
+    }
+    pub fn add_new_clip (&self) -> (usize, Arc<RwLock<MidiClip>>) {
+        let clip = Arc::new(RwLock::new(self.new_clip()));
+        let index = {
+            let mut clips = self.clips.write().unwrap();
+            clips.push(clip.clone());
+            clips.len().saturating_sub(1)
+        };
+        self.clip.store(index, Relaxed);
+        (index, clip)
+    }
+    pub fn delete_clip (&mut self, clip: &MidiClip) -> bool {
+        let index = self.clips.read().unwrap().iter().position(|x|*x.read().unwrap()==*clip);
+        if let Some(index) = index {
+            self.clips.write().unwrap().remove(index);
+            return true
+        }
+        false
+    }
+}
+
+/// Modes for clip pool
+#[derive(Debug, Clone)]
+pub enum PoolMode {
+    /// Renaming a pattern
+    Rename(usize, Arc<str>),
+    /// Editing the length of a pattern
+    Length(usize, usize, ClipLengthFocus),
+    /// Load clip from disk
+    Import(usize, FileBrowser),
+    /// Save clip to disk
+    Export(usize, FileBrowser),
+}
+
+/// Focused field of `ClipLength`
+#[derive(Copy, Clone, Debug)]
+pub enum ClipLengthFocus {
+    /// Editing the number of bars
+    Bar,
+    /// Editing the number of beats
+    Beat,
+    /// Editing the number of ticks
+    Tick,
+}
+
+impl ClipLengthFocus {
+    pub fn next (&mut self) {
+        use ClipLengthFocus::*;
+        *self = match self { Bar => Beat, Beat => Tick, Tick => Bar, }
+    }
+    pub fn prev (&mut self) {
+        use ClipLengthFocus::*;
+        *self = match self { Bar => Tick, Beat => Bar, Tick => Beat, }
+    }
+}
+
+/// Displays and edits clip length.
+#[derive(Clone)]
+pub struct ClipLength {
+    /// Pulses per beat (quaver)
+    ppq: usize,
+    /// Beats per bar
+    bpb: usize,
+    /// Length of clip in pulses
+    pulses: usize,
+    /// Selected subdivision
+    pub focus: Option<ClipLengthFocus>,
+}
+
+impl ClipLength {
+    pub fn _new (pulses: usize, focus: Option<ClipLengthFocus>) -> Self {
+        Self { ppq: PPQ, bpb: 4, pulses, focus }
+    }
+    pub fn bars  (&self) -> usize {
+        self.pulses / (self.bpb * self.ppq)
+    }
+    pub fn beats (&self) -> usize {
+        (self.pulses % (self.bpb * self.ppq)) / self.ppq
+    }
+    pub fn ticks (&self) -> usize {
+        self.pulses % self.ppq
+    }
+    pub fn bars_string  (&self) -> Arc<str> {
+        format!("{}", self.bars()).into()
+    }
+    pub fn beats_string (&self) -> Arc<str> {
+        format!("{}", self.beats()).into()
+    }
+    pub fn ticks_string (&self) -> Arc<str> {
+        format!("{:>02}", self.ticks()).into()
+    }
+}
+
+pub type ClipPool = Vec<Arc<RwLock<MidiClip>>>;
+
+pub trait HasClips {
+    fn clips <'a> (&'a self) -> std::sync::RwLockReadGuard<'a, ClipPool>;
+    fn clips_mut <'a> (&'a self) -> std::sync::RwLockWriteGuard<'a, ClipPool>;
+    fn add_clip (&self) -> (usize, Arc<RwLock<MidiClip>>) {
+        let clip = Arc::new(RwLock::new(MidiClip::new("Clip", true, 384, None, None)));
+        self.clips_mut().push(clip.clone());
+        (self.clips().len() - 1, clip)
+    }
+}
+
+#[macro_export] macro_rules! has_clips {
+    (|$self:ident:$Struct:ident$(<$($L:lifetime),*$($T:ident$(:$U:path)?),*>)?|$cb:expr) => {
+        impl $(<$($L),*$($T $(: $U)?),*>)? HasClips for $Struct $(<$($L),*$($T),*>)? {
+            fn clips <'a> (&'a $self) -> std::sync::RwLockReadGuard<'a, ClipPool>      {
+                $cb.read().unwrap()
+            }
+            fn clips_mut <'a> (&'a $self) -> std::sync::RwLockWriteGuard<'a, ClipPool> {
+                $cb.write().unwrap()
+            }
+        }
+    }
+}
diff --git a/crates/app/src/model/scene.rs b/crates/app/src/model/scene.rs
new file mode 100644
index 00000000..dc501600
--- /dev/null
+++ b/crates/app/src/model/scene.rs
@@ -0,0 +1,73 @@
+use crate::*;
+
+#[derive(Debug, Default)] pub struct Scene {
+    /// Name of scene
+    pub name:  Arc<str>,
+    /// Clips in scene, one per track
+    pub clips: Vec<Option<Arc<RwLock<MidiClip>>>>,
+    /// Identifying color of scene
+    pub color: ItemTheme,
+}
+
+impl Scene {
+    /// Returns the pulse length of the longest clip in the scene
+    pub fn pulses (&self) -> usize {
+        self.clips.iter().fold(0, |a, p|{
+            a.max(p.as_ref().map(|q|q.read().unwrap().length).unwrap_or(0))
+        })
+    }
+    /// Returns true if all clips in the scene are
+    /// currently playing on the given collection of tracks.
+    pub fn is_playing (&self, tracks: &[Track]) -> bool {
+        self.clips.iter().any(|clip|clip.is_some()) && self.clips.iter().enumerate()
+            .all(|(track_index, clip)|match clip {
+                Some(c) => tracks
+                    .get(track_index)
+                    .map(|track|{
+                        if let Some((_, Some(clip))) = track.player().play_clip() {
+                            *clip.read().unwrap() == *c.read().unwrap()
+                        } else {
+                            false
+                        }
+                    })
+                    .unwrap_or(false),
+                None => true
+            })
+    }
+    pub fn clip (&self, index: usize) -> Option<&Arc<RwLock<MidiClip>>> {
+        match self.clips.get(index) { Some(Some(clip)) => Some(clip), _ => None }
+    }
+}
+
+pub trait HasScenes: HasSelection + HasEditor + Send + Sync {
+    fn scenes (&self) -> &Vec<Scene>;
+    fn scenes_mut (&mut self) -> &mut Vec<Scene>;
+    fn scene_longest (&self) -> usize {
+        self.scenes().iter().map(|s|s.name.len()).fold(0, usize::max)
+    }
+    fn scene (&self) -> Option<&Scene> {
+        self.selected().scene().and_then(|s|self.scenes().get(s))
+    }
+    fn scene_mut (&mut self) -> Option<&mut Scene> {
+        self.selected().scene().and_then(|s|self.scenes_mut().get_mut(s))
+    }
+    fn scene_del (&mut self, index: usize) {
+        self.selected().scene().and_then(|s|Some(self.scenes_mut().remove(index)));
+    }
+    /// Set the color of a scene, returning the previous one.
+    fn scene_set_color (&mut self, index: usize, color: ItemTheme) -> ItemTheme {
+        let scenes = self.scenes_mut();
+        let old = scenes[index].color;
+        scenes[index].color = color;
+        old
+    }
+    /// Generate the default name for a new scene
+    fn scene_default_name (&self) -> Arc<str> {
+        format!("Sc{:3>}", self.scenes().len() + 1).into()
+    }
+}
+
+impl HasScenes for Tek {
+    fn scenes (&self) -> &Vec<Scene> { &self.scenes }
+    fn scenes_mut (&mut self) -> &mut Vec<Scene> { &mut self.scenes }
+}
diff --git a/crates/app/src/model/track.rs b/crates/app/src/model/track.rs
new file mode 100644
index 00000000..dc194c1e
--- /dev/null
+++ b/crates/app/src/model/track.rs
@@ -0,0 +1,150 @@
+use crate::*;
+
+#[derive(Debug, Default)] pub struct Track {
+    /// Name of track
+    pub name:       Arc<str>,
+    /// Preferred width of track column
+    pub width:      usize,
+    /// Identifying color of track
+    pub color:      ItemTheme,
+    /// MIDI player state
+    pub player:     MidiPlayer,
+    /// Device chain
+    pub devices:    Vec<Device>,
+    /// Inputs of 1st device
+    pub audio_ins:  Vec<JackAudioIn>,
+    /// Outputs of last device
+    pub audio_outs: Vec<JackAudioOut>,
+}
+
+has_clock!(|self: Track|self.player.clock);
+
+has_player!(|self: Track|self.player);
+
+impl Track {
+    pub const MIN_WIDTH: usize = 9;
+    /// Create a new track containing a sequencer.
+    pub fn new_sequencer () -> Self {
+        let mut track = Self::default();
+        track.devices.push(Device::Sequencer(MidiPlayer::default()));
+        track
+    }
+    /// Create a new track containing a sequencer and sampler.
+    pub fn new_groovebox (
+        jack:       &Jack,
+        midi_from:  &[PortConnect],
+        audio_from: &[&[PortConnect];2],
+        audio_to:   &[&[PortConnect];2],
+    ) -> Usually<Self> {
+        let mut track = Self::new_sequencer();
+        track.devices.push(Device::Sampler(
+            Sampler::new(jack, &"sampler", midi_from, audio_from, audio_to)?
+        ));
+        Ok(track)
+    }
+    /// Create a new track containing a sampler.
+    pub fn new_sampler (
+        jack:       &Jack,
+        midi_from:  &[PortConnect],
+        audio_from: &[&[PortConnect];2],
+        audio_to:   &[&[PortConnect];2],
+    ) -> Usually<Self> {
+        let mut track = Self::default();
+        track.devices.push(Device::Sampler(
+            Sampler::new(jack, &"sampler", midi_from, audio_from, audio_to)?
+        ));
+        Ok(track)
+    }
+    pub fn width_inc (&mut self) {
+        self.width += 1;
+    }
+    pub fn width_dec (&mut self) {
+        if self.width > Track::MIN_WIDTH {
+            self.width -= 1;
+        }
+    }
+    pub fn sequencer (&self, mut nth: usize) -> Option<&MidiPlayer> {
+        for device in self.devices.iter() {
+            match device {
+                Device::Sequencer(s) => if nth == 0 {
+                    return Some(s);
+                } else {
+                    nth -= 1;
+                },
+                _ => {}
+            }
+        }
+        None
+    }
+    pub fn sampler (&self, mut nth: usize) -> Option<&Sampler> {
+        for device in self.devices.iter() {
+            match device {
+                Device::Sampler(s) => if nth == 0 {
+                    return Some(s);
+                } else {
+                    nth -= 1;
+                },
+                _ => {}
+            }
+        }
+        None
+    }
+    pub fn sampler_mut (&mut self, mut nth: usize) -> Option<&mut Sampler> {
+        for device in self.devices.iter_mut() {
+            match device {
+                Device::Sampler(s) => if nth == 0 {
+                    return Some(s);
+                } else {
+                    nth -= 1;
+                },
+                _ => {}
+            }
+        }
+        None
+    }
+}
+
+pub trait HasTracks: HasSelection + HasClock + HasJack + HasEditor + Send + Sync {
+    fn midi_ins (&self) -> &Vec<JackMidiIn>;
+    fn midi_outs (&self) -> &Vec<JackMidiOut>;
+    fn tracks (&self) -> &Vec<Track>;
+    fn tracks_mut (&mut self) -> &mut Vec<Track>;
+    fn track_longest (&self) -> usize {
+        self.tracks().iter().map(|s|s.name.len()).fold(0, usize::max)
+    }
+    const WIDTH_OFFSET: usize = 1;
+    fn track (&self) -> Option<&Track> {
+        self.selected().track().and_then(|s|self.tracks().get(s))
+    }
+    fn track_mut (&mut self) -> Option<&mut Track> {
+        self.selected().track().and_then(|s|self.tracks_mut().get_mut(s))
+    }
+    /// Set the color of a track
+    fn track_set_color (&mut self, index: usize, color: ItemTheme) -> ItemTheme {
+        let tracks = self.tracks_mut();
+        let old = tracks[index].color;
+        tracks[index].color = color;
+        old
+    }
+    /// Toggle track recording
+    fn track_toggle_record (&mut self) {
+        if let Some(t) = self.selected().track() {
+            let tracks = self.tracks_mut();
+            tracks[t-1].player.recording = !tracks[t-1].player.recording;
+        }
+    }
+    /// Toggle track monitoring
+    fn track_toggle_monitor (&mut self) {
+        if let Some(t) = self.selected().track() {
+            let tracks = self.tracks_mut();
+            tracks[t-1].player.monitoring = !tracks[t-1].player.monitoring;
+        }
+    }
+}
+
+impl HasTracks for Tek {
+    fn midi_ins (&self) -> &Vec<JackMidiIn> { &self.midi_ins }
+    fn midi_outs (&self) -> &Vec<JackMidiOut> { &self.midi_outs }
+    fn tracks (&self) -> &Vec<Track> { &self.tracks }
+    fn tracks_mut (&mut self) -> &mut Vec<Track> { &mut self.tracks }
+}