What Jiggy does

Jiggy is the browser host for JigDAW: a page that loads Jigs by IRI, plays and edits a piece, and saves it as RDF. This document lists what it does now. It is a catalogue of what is built, not a plan; what is not built is in TODO.md, and where Jiggy stands against other browser DAWs is in usp.md. A figure here is checked by a test against what it counts.

There are two pages over one model and one set of operations. The studio (index.html) is the whole thing: a track view, plugin routing, automation and rendering. The simple page (simple.html) is for playing with a piece: pick a tune, press Play, change the sound. A phone starts on the simple page.

Playing

Play, Stop and Loop in the transport bar, a tempo field, a time signature field, a position readout and a level meter. The loop can be drawn on the timeline and is played as a loop.
Record keeps each track as it was heard as an audio clip, in one edit, so one undo takes the pass back out.
Web MIDI input plays into the armed track, or the selected one when none is armed, with a note stamp located by stream position.
A microphone can be recorded into a new track from the simple page.
Each channel's FX list on the Mixer tab has, for every plugin, Bypass, Move earlier and later, Replace, Controls and Remove, and a right-click or Shift+F10 menu with the same actions. The master has the same list and a Listen in mono switch, a listening aid that is not saved and not in an export.
In the studio, Mic in feeds the selected track from a microphone, chosen from a list when the browser has more than one. It is heard through that track like anything else on it; Record takes a track with a live input before its fader, so muting the track keeps a person out of the speakers and leaves the take intact.
Events are scheduled ahead of the audio clock and located by stream position, never by block count, so a note fires in the block that contains it.

The track view

Tracks. Rename, colour, lane sizes (set by plus and minus, the lane menu or Expand, or drag the bottom edge of a lane to any height; Escape cancels the drag), Level and Pan as small knobs in the row with Mute and Solo, an FX button after Solo that shows that lane's plugins under it (there only for a lane that has some), reorder (Alt with Up or Down on a name), select several and edit them together, delete with their plugins in one undoable step. A track says its own latency and how much it was delayed to line up with the others.
Timeline. A ruler with zoom, a snap grid (bar, beat, halves, quarters, eighths, off), a loop row with a draggable brace, and a playhead that follows and stops following when you scroll.
Dock. A panel under the lanes that follows the selection: a MIDI clip opens the piano roll, an audio clip its numbers, a track its chain and routing, a plugin its ports and connections.
Clips. MIDI and audio, added from a lane, imported from a file, or recorded. Move and resize by drag or by keys. Split at the playhead (S), duplicate (D), mute (M), lock (L), trim the start or end to the playhead ([ and ]), copy, cut and paste (Ctrl or Cmd with C, X and V), delete, colour. Each is one edit and one undo, with a button for each above the lanes for a phone. Cuts and trims snap to the grid. Audio clips have fades in and out, straight lines in level.
Piano roll. Draw, move, resize and delete notes with the pointer or the keyboard, with an audition. Whole-note edits sit above the grid, each one edit and one undo: quantize, transpose, softer and louder, reverse, invert, humanize, legato (each note held until the next starts) and strum (each chord rolled upward by a sixteenth).
Keys list. A Keys button and F1 open a dialog listing the keyboard shortcuts by what has to be focused (a clip, a track name, a chain plugin, an envelope point, the script box, the Browser, or anywhere). The list is data (src/ui/KeyTable.js) and tests/ui/KeyTable.test.js fires each row's keys at the real control, so a listed key that does nothing fails. Keys in the piano roll and the timeline are not listed yet, and the dialog says so.

Plugins and routing

Finding and loading. A browser panel searches a catalogue of Jigs by role, signal and other facets, loads one by IRI, and opens a collection or a preset. The page checks every file's digest before it runs.
Generated panels. Every plugin's controls are drawn from its declared ports, so there is no per-plugin interface code: knobs, selectors and switches with units spoken out, named and reachable by keyboard.
Chain strip. Under each track, its plugins in signal order with what each takes and gives. Bypass a plugin (it keeps its state, passes the signal on, and is put back instantly). Move one earlier or later (Alt with Left or Right, or the buttons), which rewires the joins as one edit.
Composite plugins. A plugin made of other plugins, such as an effects rack, loads as one plugin: one node, with the few controls its author exposed, which saves and reopens, undoes as one edit and is bypassed as a whole. Its members are loaded and wired behind it and compensated for latency as if wired by hand, and a bad member refuses the whole thing, naming it. The page generates its panel from the controls the author exposed. This was run in Chrome on 2026-10-02: it loads from an IRI, a real key played through it is governed by its Drive control, a composite pinned to a profile that has since changed is refused with the session untouched, and remove and undo restore it. A second run covered a MIDI clip played from the transport through Pulse and the rack (silent at Drive 0, a peak of 0.25 at the default), saving a session and reopening it with the setting and the author's voicing restored, and the Routing and Mixer tabs. Its catalogue search lists it as loadable, and plugins/stomp-rack/ is the worked example. Not yet done: a phone, listening to it, and loading it from a search result, which fetches the canonical address and so waits for the rack to be deployed. A composite's card has an Unpack button, on composites only: it turns the rack back into the plugins it is made of, each with the value it had inside, joined to what the rack was joined to, as one undo step (checked in Chrome: Drive 0.6 became Boost's Gain 0.6, and the author's tremolo rate became a knob). The agent tools node_unpack and composite_pack do the same, and the second describes a selection as a composite profile to publish and changes nothing. See nested-plugins.md.
Replace a plugin. A Replace button on each plugin in the chain strip opens the Browser, says which plugin the next Load takes the place of, and the Load swaps it in as one undoable edit (the agent tool is node_swap). The new plugin keeps the track, the joins whose ports it also has, the settings whose parameters it also has, the label a person gave, bypass, and the track's or master's input role; what it could not take is listed in the log in words. Refused for a composite and for a plugin with automation on it. Seen in Chrome on 2026-10-23: Tremolo in a Pulse, Tremolo, Cascade chain replaced by Boost, joined as before, undone by Ctrl+Z.
Routing matrix. Every output against every input, joined or not, by pointer or arrow keys.
Connections. Audio and MIDI, within a track or across tracks. A connection that would make a loop with no declared delay is refused with the reason, and so is a loop of MIDI connections. A MIDI connection can be watched: the last 24 events over it, in words.
Mixer channels. The Mixer tab draws each track, and the master, as a channel: a Pan knob on top, a Level fader standing up below it with the level meter standing beside it (the fader is the native range laid on its side, so the arrow keys, Home and End and the value in decibels are the platform's), then Mute over Solo. A channel is 96px wide. Channels sit side by side and wrap, with the master at the right end. Seen in Chrome on 2026-10-24: a click above the middle of the master fader raised it to +2.2 dB and Down lowered it a step each press. An FX button under each channel (FX 2 when two plugins are on it) opens a list of that track's plugins in signal order. Remove takes one off, healing the chain as Remove on the Plugins tab does, and Add plugin opens the Browser with that track as the place the next Load goes. Seen in Chrome on 2026-10-24: Add then Load put a plugin on the first track, and Remove took it off and left the focus on FX.
Mouse gestures and context menus. Right click on a clip, a track's header, an empty stretch of lane, a plugin in a chain or a mixer channel opens a menu of the actions that thing already has on buttons and keys; the Menu key or Shift+F10 opens the same menu for whatever has the focus. A menu follows the ARIA menu pattern (Up, Down, Home, End, Enter, Escape, focus back where it came from), and an action that cannot act is left out. Double click on empty lane adds a MIDI clip there on the grid, on a track's name moves the focus to its name field, and on a plugin in a chain shows its controls on the Plugins tab. Escape during a clip, track or folder drag puts it back. A single click still selects, and on a clip also opens it; Space on a focused clip adds it to the selection or takes it out, and Enter opens it. Seen in Chrome on 2026-10-24: the clip, lane, track and mixer menus, Duplicate by keyboard from a menu, Shift+F10 on a track name, and a double click on a name selecting its field. Not yet: a hover preview, menus on clips in the piano roll or on automation points.
Clip launcher. The Launcher tab is a grid: a column per track that has a MIDI input, a row per scene, and a cell per slot that says its state in words (stopped, queued, playing, stopping, or empty). Pressing a cell launches its clip at the next boundary of the Launch on setting; pressing an empty cell adds a one-bar clip and opens the piano roll; a scene button launches a row, Stop stops a track and Stop all every track. Arrow keys move over the grid, and right click or the Menu key offers Launch, Stop, Edit the notes and Delete. The tools launcher_launch, launcher_stop, launcher_quantise and launcher_state do the same for an agent. Launching changes no revision and is not saved. See clip-launcher.md.
Euclidean rhythm. Above the note roll, Note, Onsets, Steps, Rotate and A step is, with Lay rhythm, put that many onsets spread as evenly as they can be over the steps into the open clip, repeated to fill it. Notes already at that note are replaced and the rest are kept, and the text beside it says so. One undo step; the same edit as the clip_euclidean tool. Seen in Chrome: 5 in 8 sixteenths laid over a four beat clip.
Chance on a note. Choose notes in the piano roll (or none, for all of them), pick a percentage beside Chance and press Set chance: each of those notes then sounds only that often each time it comes round, drawn from where and when it falls so a render repeats exactly, and again on every pass of a loop. A note with a chance is a half-filled square in the roll and is said as "50 percent chance of sounding"; 100% takes the chance away. The tool is clip_transform_notes with setChance, and chance can be given on a note to clip_set_notes.
Show. A Show control at the left of the transport bar chooses how much of the studio is drawn: Simple (13 controls, no tabs), Standard (22, five tabs: Arrangement, Plugins, Mixer, Launcher and Settings) or Advanced (25, seven tabs). A control the step does not reach is left out of the layout, the tab order and the accessibility tree, not disabled. A narrow screen starts on Simple and a wide one on Standard, a choice is remembered in this browser, and asking from code for a tab the step does not draw says which step does and offers to show it. The list is src/ui/Show.js and tests/web/Show.test.js binds it to the page. Seen in Chrome on 2026-10-26. See learning-curve.md.
Start screen. An empty arrangement offers Play a tune (the bundled presets, the same names as the simple page), Start a new piece (a track with a sound, an empty track, find a plugin), From a template (shown only when some are saved) and Open a saved piece, each a button under its own heading. See learning-curve.md. Seen in Chrome on 2026-10-26.
Add a track. Add track in the arrangement, and "A track with a sound" on the start screen, open a dialog of the instruments this host can run. The sounds are listed as Instruments, Make notes for me (a generator and an instrument on one track: a bass line, a melody), Drums and Voice (a microphone). Hear plays four notes through a trial track that is taken away again (never an undo step), Add keeps the sound on a new track as one undo step, and An empty track and Cancel are there too. A drum sound can be a kit played by a beat generator ("DrumKit with DrumGen"): the two are loaded and joined on one track, a key or a clip plays the kit, Play runs the beat, and the Plugins tab opens on the Feel pad. Seen in Chrome on 2026-10-26, with the level measured on the trial track. See learning-curve.md.
The transport in groups. The bar is named groups (Sounds and help, Play, Tempo and time, Input, Edit, File, Output) so a screen reader says where a control is. Play, Stop, Record, Save and Open show their words beside the icon (not below 480px), and Panic, Stems and Install are under More, which Advanced draws. Seen in Chrome on 2026-10-26. See learning-curve.md.
Repeating a clip. A MIDI clip has a loop mark at its top right: drag it to repeat the clip to a longer length, or press R to repeat it once more, or use Repeat once more and Stop repeating on its menu. A repeated clip draws its notes again for each repeat and a line where each starts, and a repeat is one undo step. Seen in Chrome on 2026-10-26. See learning-curve.md.
Light and dark themes. The studio, the simple page and the Reel page are light until a person chooses, and the Theme control in Settings offers Light, Dark and Match my device, kept in this browser and shared by those pages. The colours are tokens set once per theme, so a rule that wrote a colour of its own is a test failure, and tests/web/Theme.test.js computes the contrast of the text, line and outline pairs in both themes (4.5 to 1 for text, 3 to 1 for a line). The test found white on the dark theme's accent blue at 4.0 to 1, which is why that blue is slightly darker than it was. Not themed: the plugin gallery page, and a plugin's own interface or skin, which draws its own colours. Seen in Chrome on 2026-10-26.
Primary controls. A plugin's profile can rank its ports with pprops:displayPriority (LV2's own term, higher matters more). The generated panel draws the ranked ports first as one flat row of knobs, highest first, and puts the others under a "More controls (N)" disclosure with their groups; a profile that ranks none, or all, is drawn whole. DrumKit ranks 14 of its 75 (the master controls and each voice's level). Seen in Chrome on 2026-10-26, loading the local copy. See plugin-profiles.md.
Help for a control. A plugin's port can carry an rdfs:comment, one sentence. The generated panel shows it in a line under the heading while the control is hovered or focused, with the control's name in bold, and gives it to a screen reader as the control's description. Escape puts it away and moves nothing. A plugin with no comments gets no line. Pulse, DrumKit, BassGen, DrumGen, MelGen, Moka, Monochord, Canticle and Mop have help and rank their main controls. Seen in Chrome on 2026-10-26. See plugin-profiles.md.
A pad for two controls. DrumGen, BassGen and MelGen each show a square called Feel above their controls, with a word at each end of its axes and a selector for the style beside it: dragging it sets two controls at once (density across; variation, hold or leap up), and it follows them when they move any other way. It is a pointer shortcut. The two controls stay on the panel for a keyboard and a screen reader, and a caption says which is across and which is up. See plugin-profiles.md.
Loops. A Loops button in the arrangement tools, and "A loop to start from" on the start screen, open 19 starter MIDI loops by kind (Drums, Bass, Chords, Melody), each with a length, a key where it has one and a line about it, and a starter set at the top: Deep house that writes itself, four parts made by Euclidean rules over four chords, added together as four tracks at 120 BPM. Add puts the loop at the playhead on the selected track when its instrument suits it, or makes a track with a suitable sound at the start, as one undo step; Hear plays it through the selected track's instrument. The loops are original and CC0-1.0. See learning-curve.md.
Keyboard help. A control with a title shows it in a small tip beside it when it takes the focus by keyboard, unless it only repeats the control's name; Escape puts it away. A plugin's own controls use the panel's help line instead.
Time readout. The transport bar shows the position as minutes, seconds and tenths (from the tempo map, so it follows tempo changes and loops) beside the bar and beat.
Settings. A Settings tab holds what is not part of playing: Line tracks up for latency, the project's title, author and notes, and the Local agent and Agent bridge connections.
Output meter with a clip hold. The meter beside the transport shows the level of the mix, and a Clip button appears when it reached full scale and stays until pressed. Every strip on the Mixer tab has a level meter of its own with the held peak in decibels beside it, and the Master channel lists the plugins on the master.
Sends, buses and the master. Sends before or after the fader, a track's output to another track, and a master with level, pan and mute, all acting on the sound. A cycle of them is refused. Audio sent or bused to a track arrives at the plugin the track names as its audio input, so a reverb on a bus is in the path, and the master has a chain of its own the same way: plugins on the master, and the one the mix of every track arrives at. Generative Gamelan has its reverb there. MIDI between tracks is a connection between two plugins, or a MIDI send from one track to another, which delivers to the plugin the target plays its MIDI into; Generative Gamelan's Conductor drives both lines by two MIDI sends. A MIDI send or connection can carry a note range, so one keyboard is split between two instruments, and either end of a send can be a composite plugin.
Sidechain. A plugin can mark an input as a key, and the matrix names it "Sidechain key". Dynamix ducks from a kick on another track.
Latency. Declared latency is compensated between connected plugins, and tracks are delayed so that parallel tracks arrive together, with a switch.

Automation

An envelope on any plugin parameter, on the master level or pan, or on the tempo, with step, linear and smooth curves between points. Played on the audio clock, looped passes included, and Stop puts every parameter back to the value set by hand.
Lanes under each track and a row for the master and tempo: each point is a button named in words, moved by keys or by dragging, with a click on empty lane to add one. Every gesture is one undo.
A hand edit while a lane plays takes over at once and pauses that lane until Stop.
A tempo envelope is the tempo map, so notes, audio clips and the position all follow it.

Rendering

Export renders the mix to a WAV in the page, faster than it plays, without disturbing playback. The loop, when it is on, is what is rendered.
Stems render every track that makes sound to its own WAV in one zip.
Export MIDI saves the notes of every unmuted MIDI clip as a Standard MIDI File (format 1, 480 ticks to the quarter): a conductor track with the tempo and time signature changes, then one track per project track that has notes, each on its own channel from 1 (10 is skipped, as General MIDI keeps it for drums). Audio clips, muted clips and mixing are not in it.
Controller and pitch bend lanes sit under the note roll: velocity bars for each note, or a lane for pitch bend, modulation, volume, pan, expression, sustain or any controller number. A clip holds the events as a step curve, plays them with its notes, and carries them through split, copy and MIDI import and export. Where a loop comes round, or playing starts part way in, each controller is set to what it held at that point, and a pitch bend wheel with nothing earlier to say goes back to rest.
Undo history under the arrangement lists every edit in words, with the current state marked; choosing one goes there by undoing or redoing. It holds the last 100 edits and is not saved with the session.
Mute and Solo are small lettered squares, an M that turns red and an S that turns yellow. The word is still the control's name for a screen reader, and on is a filled square with an underlined letter, so it does not rely on colour.
Project section under the arrangement keeps a title, an author and notes with the session. They are saved in the file, are not an undo step, and an agent reads and sets them with project_info.
Templates keep the open session in this browser under a name, and start a new session from one. They stay until deleted, and they are not saved with a session or shared between browsers.
Tap beside the tempo sets it from your taps: the average gap of the last five, started again after a two second pause.
A plugin's text (a lyric for Sam, a .scl for Retune) is a text area in its generated panel, with its limit in bytes, an Apply button and Ctrl+Enter, on the full page and the simple page. It shows what the plugin has loaded and keeps what you have typed and not applied.
Folders have a bar with a hide and show button, Move up and Move down, and a grip to drag the whole folder to another row. A track's grip and a folder's grip can also drop onto another folder's bar, which lands above that folder's first track when dragged up and just above its bar when dragged down, never inside it. That is the way onto a collapsed folder, whose rows are not drawn. Whether a folder is hidden is saved with the session.
Loop a clip repeats a MIDI clip's first beats to fill its length. Type a loop length in the note roll (Loop, Clear loop), and the clip plays, exports to a MIDI file and is announced to a screen reader as looping. A note that starts after the loop end is kept and not played while the loop is set. Splitting a looped clip, or trimming its start, writes the repeats into the notes and clears the loop.
Rec MIDI plays the transport and keeps what you play on a MIDI keyboard (the armed tracks, or the selected one) or the on-screen keys as one MIDI clip per track, from where the take began and a whole number of bars long, with the pitch bend wheel and controllers kept as events. Stop ends it too, and one undo takes the take back. It is separate from Record, which keeps audio.
Import MIDI adds each part of a format 0 or 1 Standard MIDI File as a new track with one clip from beat zero, in one edit (one undo). A project with no MIDI clips yet also takes the file's tempo and time signature changes; one that already has music keeps its own and only gains the notes, and the log says which. A file that counts time in frames, is cut short, or is not MIDI is refused with the reason and changes nothing. Files over 8 MB are not imported.
Freeze renders one track as heard to an audio clip on a new track and mutes the original, in one edit.
Rendering uses a second engine built from a snapshot of the session: the same plugins, scheduler, clips, envelopes and transport messages, with the audio context suspended each tick.

Sessions

A session is RDF (Turtle), or a zip of it with its audio and a separate editor.ttl for layout, colours and positions. Layout is kept apart from the model and is not part of undo.
Undo and redo cover every edit; a changeset is atomic and carries a revision.
Save and Open, nine bundled presets that play a piece on their own, and a piece carried between the two pages: following the link to the other page keeps the open session and the other page offers it.

The simple page

Six tunes as big buttons, Play and Stop, a Speed slider in plain words, and a card per instrument with On and Off, its loudness, and "Change the sound".
"Change the sound" opens a rack screen for that track: its plugins as generated panels, with Back, a history entry so the browser's Back works too.
Record your voice into a new track, save the piece, and make a sound file (a WAV).
Targets are 44px and the layout is one column with no sideways scroll at phone width.

The Reel page

reel.html is for writing Reel scripts (livecoding.md), on a phone first. A menu and an Open button pick one of the bundled pieces; Play, Stop, speed and the meter stay at the foot of the screen.
Four tabs. Script is the editor with Run, Check only and Stop, and saves or opens a .reel file (opening one does not run it). Examples has ready-made scripts, each written for one bundled piece: "Edit this" puts it in the editor, "Play it" opens the piece, starts the music and runs it. This piece lists the names a script can use in the open piece and their parameters, with an Insert button that writes the line to set one. Reference is the language: statements, units, functions, naming and limits, with an Insert button on each example.
The examples, the reference and the Insert lines are checked by tests against the real pieces, plugin profiles and parser, so none of them can name a parameter or a form that is not there.

Installing and offline

A web app manifest and icons, a service worker that keeps the page and what you have opened, an update notice that never reloads under a playing piece, an install button, and an offline indicator. A cached plugin is still checked against its digest when it is run.

For agents

67 tools over the same dispatcher the page uses, through WebMCP: search and load plugins, edit tracks and clips, connect and bypass and reorder nodes, set and reset parameters, write envelopes, undo and redo, and play and stop. Nothing an agent does goes around the operations the interface uses, so it is undoable and checked the same way (webmcp.md).
A Script tab drives the plugins from text, in Reel (livecoding.md): every plugin a script loads is fetched and validated before anything runs, a script with a problem changes nothing and says which lines, a new script takes over at the next bar line (or now), and one run is one undo step. Control+Enter runs it and Control+Shift+Enter runs it now. Checked in Chrome, at phone width too.

The plugins

36 plugins are served beside the page, written in Rust, C++, JavaScript and JSFX, each described by a profile and loadable by its IRI:

Instruments: Pulse (subtractive), Canticle (tonal), DrumKit, Mop (OPL3 FM), 8-Bit 8asterd (AY chip).
Generators: MelGen, BassGen, DrumGen, Ground, Cadence and Counterpointer play a piece from a few settings and the transport.
MIDI processors: Dice (probability gate) and MIDI Filter (channel, transpose, note range).
Effects: Cascade (reverb), Ferrite (neural amp and cabinet or room), Dynamix (compressor, limiter, clipper, with a sidechain key), Squelch (acid filter), Tremolo, Quefrency (formant and pitch), Lookahead, Boost, and three JSFX effects (gain trim, one-pole filter, soft clipper).

9 presets are bundled: Glass Hours (a 40 bar piece of clips), Chiptune, Acid, Generative through effects, Sam in a room, Fender into the Ropery, Fugue, Generative Gamelan, and Through Keyframe. Each is played offline in a test and must put sound on every track that has a sound maker.

Built to be used by everyone

Every control has a name, a role and a value said as text. The keyboard reaches everything the pointer does. State is never colour alone. A control nobody can use is left out, not shown disabled.
Touch targets are at least 44px and text inputs 16px. One column below 720px, with no sideways scroll, measured in a real browser.
Standard icons carry their words as their accessible name.