ABC sheet music + Strudel live coding studio with ext-apps widgets, harmony tools, and share links.
MCP Music Studio
The io.github.linxule/mcp-music-studio MCP server provides an “ABC sheet music + Strudel live coding” music studio for AI. It supports two modes: scored composition using ABC notation with sheet music, and live performance using Strudel with TidalCycles. Its interactive UI renders inline in Claude Desktop, claude.ai, and other MCP clients.
🛠️ Key Features
Two-mode studio: scored composition (ABC notation + sheet music) and live performance (Strudel + TidalCycles)
Interactive UI that renders inline in MCP clients
Remote server endpoint for MCP clients
🚀 Use Cases
Compose music with ABC notation and view sheet music
Run live coding music workflows with Strudel and TidalCycles
Use compatible MCP clients to access the studio via a shared link
⚡ Developer Benefits
Works as a remote MCP server (.../mcp) without install
Uses ext-apps widgets and includes harmony tools and share links (as described)
⚠️ Limitations
Documentation excerpt does not specify available tools in detail (toolCount: 5) or the full feature set beyond the described modes and UI.
Topics
abcjsmcpmcpappsstrudelmcp-servermusicext-apps
Captured live from the server via tools/list.
play-sheet-music
Compose and play sheet music with visual notation, multi-instrument audio, and style presets. Write ABC notation for melodies, arrangements, harmonized pieces, or well-known tunes. Add a style (rock, jazz, bossa, waltz, folk...) for automatic drums, bass, and chord accompaniment. Returns a parse-status confirmation and renders the player; it does not return raw audio. Use get-music-guide for genre templates, instrument lists, and ABC syntax reference.
The music player renders inline with interactive playback controls.
Parameters8
abcNotation
string
optional
ABC notation string. Include chord symbols ("C", "Am7") above notes for auto-accompaniment with style presets.
title
string
optional
Piece title (overrides T: in ABC). Shown in the widget header and used as the filename stem for the WAV/MIDI downloads.
instrument
string
optional
Default instrument for the main voice — any of the 128 General MIDI names (e.g. 'Flute', 'Cello', 'Banjo', 'Alto Sax'). Matching is fuzzy and picks the lowest GM program among the hits, so 'sax' gives Soprano Sax; the result text names what you actually got whenever it isn't what you asked for. Use get-music-guide with topic 'instruments' for the full list, or %%MIDI program N in the ABC to set a program per voice.
style
string
optional
Accompaniment style. Adds drums, bass, and chord patterns automatically. Your ABC needs chord symbols ("C", "Am") for accompaniment to work. Options: rock, jazz, bossa, waltz, march, reggae, folk, classical.
tempo
number
optional
Tempo in BPM (40-240). Overrides Q: in ABC notation.
swing
number
optional
Swing as the share of the beat given to its first half. 50 = straight, 60 ≈ 3:2, 66 = triplet swing, 75 = maximum (dotted eighth + sixteenth). Anything at or below 50 is treated as no swing. Only takes effect in an x/4 or x/8 meter.
drumIntro
integer
optional
Bars of count-in before the melody starts (0-8). Needs a style preset — the count-in is played by that style's drum kit, so without a style you get silent bars instead.
transpose
integer
optional
Transpose by semitones (-12 to 12). Positive=higher, negative=lower. Rewrites the notation and the key signature, so the printed score matches what plays.
Raw schema
{
"type": "object",
"properties": {
"abcNotation": {
"default": "X:1\nT:Twinkle, Twinkle Little Star\nM:4/4\nL:1/4\nK:C\nC C G G | A A G2 | F F E E | D D C2 |\nG G F F | E E D2 | G G F F | E E D2 |\nC C G G | A A G2 | F F E E | D D C2 |",
"description": "ABC notation string. Include chord symbols (\"C\", \"Am7\") above notes for auto-accompaniment with style presets.",
"type": "string",
"maxLength": 65536
},
"title": {
"description": "Piece title (overrides T: in ABC). Shown in the widget header and used as the filename stem for the WAV/MIDI downloads.",
"type": "string"
},
"instrument": {
"description": "Default instrument for the main voice — any of the 128 General MIDI names (e.g. 'Flute', 'Cello', 'Banjo', 'Alto Sax'). Matching is fuzzy and picks the lowest GM program among the hits, so 'sax' gives Soprano Sax; the result text names what you actually got whenever it isn't what you asked for. Use get-music-guide with topic 'instruments' for the full list, or %%MIDI program N in the ABC to set a program per voice.",
"type": "string"
},
"style": {
"description": "Accompaniment style. Adds drums, bass, and chord patterns automatically. Your ABC needs chord symbols (\"C\", \"Am\") for accompaniment to work. Options: rock, jazz, bossa, waltz, march, reggae, folk, classical.",
"type": "string",
"enum": [
"rock",
"jazz",
"bossa",
"waltz",
"march",
"reggae",
"folk",
"classical"
]
},
"tempo": {
"description": "Tempo in BPM (40-240). Overrides Q: in ABC notation.",
"type": "number",
"minimum": 40,
"maximum": 240
},
"swing": {
"description": "Swing as the share of the beat given to its first half. 50 = straight, 60 ≈ 3:2, 66 = triplet swing, 75 = maximum (dotted eighth + sixteenth). Anything at or below 50 is treated as no swing. Only takes effect in an x/4 or x/8 meter.",
"type": "number",
"minimum": 0,
"maximum": 75
},
"drumIntro": {
"description": "Bars of count-in before the melody starts (0-8). Needs a style preset — the count-in is played by that style's drum kit, so without a style you get silent bars instead.",
"type": "integer",
"minimum": 0,
"maximum": 8
},
"transpose": {
"description": "Transpose by semitones (-12 to 12). Positive=higher, negative=lower. Rewrites the notation and the key signature, so the printed score matches what plays.",
"type": "integer",
"minimum": -12,
"maximum": 12
}
},
"$schema": "http://json-schema.org/draft-07/schema#"
}
play-live-pattern
Live-code music patterns using TidalCycles mini-notation in JavaScript. Layer drums, synths, and bass with stack(). Choose from 71 drum machine banks, 128 GM instruments, built-in synths, and a full effects chain. Patterns play in a REPL the user can edit directly. Add .pianoroll() to a pattern to show a live piano-roll animation in the widget (or .punchcard()/.scope()/.spectrum() — one draw method per pattern). For a custom animated background, start the code with `await initHydra()` and write Hydra shader code — H(pattern) locks it to the sequence, and `() => a.fft[0]` makes it react to the audio itself (Strudel's output, not the mic); see get-strudel-guide topic 'hydra'. Rather not hand-write one? `visuals` picks a ready-made animation for code that has none (pianoroll/punchcard/scope/spectrum, or hydra-kaleid/pulse/wash/feed). `theme` sets the code-editor colour scheme, which also tints the visuals — match it to the mood (teletext chiptune, sonicPink synthwave, nord ambient, gruvboxDark lofi). Each call creates a NEW player rather than updating the last one — for a tweak, send the whole revised pattern and ask the user to stop the previous one. Use get-strudel-guide for genre templates, sound references, and advanced features like arrangement and sample loading.
The Strudel REPL renders inline with an editable code editor, visualizations, and playback controls.
Parameters6
code
string
required
Strudel pattern code. Uses TidalCycles mini-notation in JavaScript. Use stack() to layer drums, bass, and melody. Set tempo with setcps(bpm/60/4) or use the bpm parameter. The REPL plays the LAST expression: setup lines (await initHydra(), all(), setcps()) go BEFORE the pattern. Double quotes are mini-notation — use single quotes for plain strings and URLs. One draw method per pattern; pass a.fft values as functions (() => a.fft[0]).
title
string
optional
Pattern title displayed in the widget header (e.g. 'Midnight Rain').
bpm
number
optional
Tempo in BPM (40-300). Converts to setcps() automatically.
autoplay
boolean
optional
Start playing immediately (default: true). May require user click due to browser autoplay policy.
visuals
string
optional
Ready-made visual, for when the code has none of its own. pianoroll/punchcard/scope/spectrum draw onto the 2D canvas behind the code; hydra-kaleid (rotating kaleidoscope), hydra-pulse (shape driven by a rhythm), hydra-wash (slow ambient noise) and hydra-feed (the piano roll mirrored and trailed) are WebGL shader backgrounds. A preset fills the MISSING layer: a hydra preset is skipped only if the code already calls initHydra(), a 2D preset only if the code already has a draw method — so hydra-wash layers happily under your own .pianoroll(). Hydra presets are dropped for viewers who prefer reduced motion. Writing your own visual is still the better result (draw methods: topic 'visuals'; shaders: topic 'hydra').
theme
string
optional
Editor colour theme; the visuals stage and its readability scrim are derived from it, so it also decides whether a shader sits on a dark or light ground — prefer a dark one when the visual is the point (e.g. 'nord', 'sonicPink', 'tokyoNight'). Not carried into share links or the browser fallback.
Raw schema
{
"type": "object",
"properties": {
"code": {
"type": "string",
"maxLength": 65536,
"description": "Strudel pattern code. Uses TidalCycles mini-notation in JavaScript. Use stack() to layer drums, bass, and melody. Set tempo with setcps(bpm/60/4) or use the bpm parameter. The REPL plays the LAST expression: setup lines (await initHydra(), all(), setcps()) go BEFORE the pattern. Double quotes are mini-notation — use single quotes for plain strings and URLs. One draw method per pattern; pass a.fft values as functions (() => a.fft[0])."
},
"title": {
"description": "Pattern title displayed in the widget header (e.g. 'Midnight Rain').",
"type": "string"
},
"bpm": {
"description": "Tempo in BPM (40-300). Converts to setcps() automatically.",
"type": "number",
"minimum": 40,
"maximum": 300
},
"autoplay": {
"description": "Start playing immediately (default: true). May require user click due to browser autoplay policy.",
"type": "boolean"
},
"visuals": {
"description": "Ready-made visual, for when the code has none of its own. pianoroll/punchcard/scope/spectrum draw onto the 2D canvas behind the code; hydra-kaleid (rotating kaleidoscope), hydra-pulse (shape driven by a rhythm), hydra-wash (slow ambient noise) and hydra-feed (the piano roll mirrored and trailed) are WebGL shader backgrounds. A preset fills the MISSING layer: a hydra preset is skipped only if the code already calls initHydra(), a 2D preset only if the code already has a draw method — so hydra-wash layers happily under your own .pianoroll(). Hydra presets are dropped for viewers who prefer reduced motion. Writing your own visual is still the better result (draw methods: topic 'visuals'; shaders: topic 'hydra').",
"type": "string",
"enum": [
"none",
"pianoroll",
"punchcard",
"scope",
"spectrum",
"hydra-kaleid",
"hydra-pulse",
"hydra-wash",
"hydra-feed"
]
},
"theme": {
"description": "Editor colour theme; the visuals stage and its readability scrim are derived from it, so it also decides whether a shader sits on a dark or light ground — prefer a dark one when the visual is the point (e.g. 'nord', 'sonicPink', 'tokyoNight'). Not carried into share links or the browser fallback.",
"type": "string",
"enum": [
"strudelTheme",
"algoboy",
"archBtw",
"androidstudio",
"atomone",
"aura",
"bbedit",
"blackscreen",
"bluescreen",
"bluescreenlight",
"CutiePi",
"darcula",
"dracula",
"duotoneDark",
"eclipse",
"fruitDaw",
"githubDark",
"githubLight",
"greenText",
"gruvboxDark",
"gruvboxLight",
"sonicPink",
"materialDark",
"materialLight",
"monokai",
"noctisLilac",
"nord",
"redText",
"solarizedDark",
"solarizedLight",
"sublime",
"teletext",
"tokyoNight",
"tokyoNightDay",
"tokyoNightStorm",
"vscodeDark",
"vscodeLight",
"whitescreen",
"xcodeLight"
]
}
},
"required": [
"code"
],
"$schema": "http://json-schema.org/draft-07/schema#"
}
get-music-guide
Returns detailed reference material for music composition. Topics: instruments (GM instrument list + combos), drums (patterns + percussion notes), abc-syntax (notation reference), arrangements (multi-voice patterns), genres (complete ABC templates for jazz/blues/folk/rock/bossa/classical), styles (what each style preset does), midi-directives (%%MIDI reference).
Parameters1
topic
string
required
Reference topic. Start with 'genres' for complete examples, 'styles' to understand presets, or 'instruments' for the full instrument list.
Raw schema
{
"type": "object",
"properties": {
"topic": {
"type": "string",
"enum": [
"instruments",
"drums",
"abc-syntax",
"arrangements",
"genres",
"styles",
"midi-directives"
],
"description": "Reference topic. Start with 'genres' for complete examples, 'styles' to understand presets, or 'instruments' for the full instrument list."
}
},
"required": [
"topic"
],
"$schema": "http://json-schema.org/draft-07/schema#"
}
get-strudel-guide
Reference material for Strudel live coding (performance mode). Topics: mini-notation (pattern syntax), sounds (synths, 71 drum banks, 128 GM instruments, 128 vcsl orchestral/percussion samples), effects (filters, reverb, delay, FM synthesis, envelopes), patterns (transformations, probability, euclidean, arrangement), genres (complete templates: techno/house/dnb/ambient/jazz/lofi/synthwave), tips (tempo, common mistakes, ABC↔Strudel crossover), visuals (pianoroll/scope draw methods, the visuals presets and the theme parameter), hydra (WebGL shader backgrounds: initHydra, H(pattern), the audio-reactive a.fft object, recipes, cheat-sheet), advanced (sample loading, wavetables, ZZFX, continuous signals, chord voicings).
Parameters1
topic
string
required
Reference topic. Start with 'genres' for working templates, 'sounds' for instruments, 'visuals' for draw methods and presets, 'hydra' for shader backgrounds, 'advanced' for sample loading.
Raw schema
{
"type": "object",
"properties": {
"topic": {
"type": "string",
"enum": [
"mini-notation",
"sounds",
"effects",
"patterns",
"genres",
"tips",
"visuals",
"hydra",
"advanced"
],
"description": "Reference topic. Start with 'genres' for working templates, 'sounds' for instruments, 'visuals' for draw methods and presets, 'hydra' for shader backgrounds, 'advanced' for sample loading."
}
},
"required": [
"topic"
],
"$schema": "http://json-schema.org/draft-07/schema#"
}
search-music-docs
Search detailed documentation for Strudel live coding or ABC/ABCJS notation. Returns relevant code examples and explanations from the official docs. Use this when the curated guides (get-strudel-guide, get-music-guide) don't cover what you need — for specific functions, advanced techniques, or when you're unsure about syntax. Powered by semantic search over strudel.cc and ABCJS docs.
Parameters2
query
string
required
What you want to know. Be specific. Good: 'how to use FM synthesis with envelope' or 'chop and slice sample manipulation'. Bad: 'effects' or 'help'.
library
string
optional
Which library to search: 'strudel' for live coding patterns, 'abcjs' for sheet music notation.
Raw schema
{
"type": "object",
"properties": {
"query": {
"type": "string",
"maxLength": 500,
"description": "What you want to know. Be specific. Good: 'how to use FM synthesis with envelope' or 'chop and slice sample manipulation'. Bad: 'effects' or 'help'."
},
"library": {
"default": "strudel",
"description": "Which library to search: 'strudel' for live coding patterns, 'abcjs' for sheet music notation.",
"type": "string",
"enum": [
"strudel",
"abcjs"
]
}
},
"required": [
"query"
],
"$schema": "http://json-schema.org/draft-07/schema#"
}
analyze-harmony
Music theory helper: name a chord from notes, guess the key, get a progression, or list what fits a key. Returns both the ABC chord-symbol spelling (for play-sheet-music) and the Strudel form (for play-live-pattern). Tasks: detect-chord (notes -> chord name + what to play next), detect-key (notes or chords -> best key + diatonic chords), suggest-progression (key [+ romanNumerals] -> chord symbols), scale-for-chord (chords -> the scale to improvise over each), key-chords (key -> every diatonic triad, seventh, and chord scale). Use it before writing chord symbols for a style preset, or to check a harmonization.
Parameters5
task
string
required
What to work out. detect-chord/detect-key need notes or chords; suggest-progression/key-chords need a key.
notes
array
optional
Note names, e.g. ["c4","e4","g4","b4"] or ["C","Eb","G"]. For detect-chord/detect-key.
chords
array
optional
Chord symbols, e.g. ["Dm7","G7","Cmaj7"]. For detect-key/scale-for-chord.
key
string
optional
Key, e.g. "C", "A minor", "F# major". For suggest-progression/key-chords.
romanNumerals
array
optional
Roman numerals to render in the key, e.g. ["ii7","V7","Imaj7"] or ["I","V","vi","IV"]. Optional for suggest-progression — omit it to get common progressions instead.
Raw schema
{
"type": "object",
"properties": {
"task": {
"type": "string",
"enum": [
"detect-chord",
"detect-key",
"suggest-progression",
"scale-for-chord",
"key-chords"
],
"description": "What to work out. detect-chord/detect-key need notes or chords; suggest-progression/key-chords need a key."
},
"notes": {
"description": "Note names, e.g. [\"c4\",\"e4\",\"g4\",\"b4\"] or [\"C\",\"Eb\",\"G\"]. For detect-chord/detect-key.",
"maxItems": 64,
"type": "array",
"items": {
"type": "string"
}
},
"chords": {
"description": "Chord symbols, e.g. [\"Dm7\",\"G7\",\"Cmaj7\"]. For detect-key/scale-for-chord.",
"maxItems": 64,
"type": "array",
"items": {
"type": "string"
}
},
"key": {
"description": "Key, e.g. \"C\", \"A minor\", \"F# major\". For suggest-progression/key-chords.",
"type": "string"
},
"romanNumerals": {
"description": "Roman numerals to render in the key, e.g. [\"ii7\",\"V7\",\"Imaj7\"] or [\"I\",\"V\",\"vi\",\"IV\"]. Optional for suggest-progression — omit it to get common progressions instead.",
"maxItems": 64,
"type": "array",
"items": {
"type": "string"
}
}
},
"required": [
"task"
],
"$schema": "http://json-schema.org/draft-07/schema#"
}
convert-abc-to-strudel
Turn an ABC melody into Strudel mini-notation so a scored piece can be remixed live. Returns runnable code — setcps() from the Q: tempo, one [...] bar group per bar inside note("<...>"), with a chord("<...>").voicing() layer stacked alongside it when the ABC has chord symbols (one stack(), because Strudel plays only the last expression) — then pass it to play-live-pattern. Durations become @ weights, rests become ~, triplets nest, the key signature is folded into the note names, and %%MIDI program picks the sound. Lists what was lost (grace notes, dynamics, repeats, lyrics, other voices, inline tempo changes, a short final bar, ABC's own gchord/drum accompaniment). Pick a single voice with `voice`; re-run per voice and stack() them for a full arrangement.
Parameters3
abcNotation
string
required
ABC notation to convert (the same string you'd pass to play-sheet-music).
voice
integer
optional
Which voice to convert, 1-based, counted across all staves (default 1). Multi-voice tunes report how many voices there are.
sound
string
optional
Strudel sound for the melody (defaults to the tune's %%MIDI program, else "gm_piano"). Use a GM soundfont name like gm_flute or gm_epiano1 — see get-strudel-guide topic 'sounds'.
Raw schema
{
"type": "object",
"properties": {
"abcNotation": {
"type": "string",
"maxLength": 65536,
"description": "ABC notation to convert (the same string you'd pass to play-sheet-music)."
},
"voice": {
"description": "Which voice to convert, 1-based, counted across all staves (default 1). Multi-voice tunes report how many voices there are.",
"type": "integer",
"minimum": 1,
"maximum": 9007199254740991
},
"sound": {
"description": "Strudel sound for the melody (defaults to the tune's %%MIDI program, else \"gm_piano\"). Use a GM soundfont name like gm_flute or gm_epiano1 — see get-strudel-guide topic 'sounds'.",
"type": "string"
}
},
"required": [
"abcNotation"
],
"$schema": "http://json-schema.org/draft-07/schema#"
}
Two-mode creative music studio for AI: scored composition (ABC notation with sheet music) and live performance (Strudel live coding with TidalCycles). Interactive UI renders inline in Claude Desktop, claude.ai, and other MCP clients.
One continuous live set through the widget — every section a hot-swapped re-evaluation on the same clock. Full video: 16:9 1080p60 · 3:4 for phones. Made with dev/perform.html and an OBS Browser Source (see scripts/showcase/).
Quick Start — No Install Required
Paste this URL into any MCP client that supports remote servers:
code
https://mcp-music-studio.linxule.workers.dev/mcp
Claude Desktop / claude.ai:
Settings → Connectors → Add Connector → paste the URL above → done.
Claude Code:
bash
claude mcp add --transport http music-studio https://mcp-music-studio.linxule.workers.dev/mcp
That's it — ask Claude to play a song or create a beat.
What You Get
Scored Composition (ABC Notation)
Write sheet music → see it rendered → hear it played with multi-instrument audio.
All 128 General MIDI instruments — named and fuzzy-matched ("sax" → Soprano Sax); the result text says what it actually resolved to when that isn't what you asked for
Visual sheet music — notes highlight as they play
Streaming render — sheet music appears as the AI types
Edit in place — open the ABC source pane in the widget, fix a bar, re-render without another tool call
Real transposition — transpose rewrites the notation and the key signature, so the printed score matches what plays
Swing and count-in — swing is the share of the beat given to its first half (50 = straight, 66 = triplet, 75 = max; ≤50 is no swing), drumIntro adds up to 8 bars of count-in from the style's drum kit
Selectable sound banks — FluidR3 (default), MusyngKite (fuller), or a lightweight dry bank, switched live from the toolbar
WAV download — export audio as WAV files directly from the UI
MIDI download — export a standard MIDI file straight from the score, no playback needed first. It is the score: abcjs applies swing during playback only, so the exported file has none
Full effects chain — filters, reverb, delay, FM synthesis
Editable REPL — users can tweak the code and hear changes instantly
Live visuals — add .pianoroll() / .punchcard() / .scope() / .spectrum() to animate behind the code (native strudel.cc overlay)
Hydra shader backgrounds — await initHydra() + Hydra code for fully custom, music-synced WebGL visuals. H(pattern) locks a shader parameter to the sequence, feedStrudel post-processes the piano roll
Audio-reactive shaders — a.fft[0], a0(), a.setBins(6) and the rest of Hydra's audio API work verbatim, driven by Strudel's own output rather than the microphone (no permission prompt, no room noise)
visuals preset — one enum value (pianoroll, punchcard, scope, spectrum, hydra-kaleid, hydra-pulse, hydra-wash, hydra-feed) gives a bare pattern something to paint. Never overrides code that already visualises itself
theme — 39 CodeMirror colour schemes; the visuals stage and its readability scrim are derived from the active theme, so light themes stay readable
Stage mode — hide the code and let the visuals fill the frame (composes with the host's fullscreen)
Honest runtime feedback — evaluation errors, unknown sound names, and stops the user triggered are reported back to the model as they happen, so it never answers about a silent widget as if the music were still playing
Server-side validation — the local server evaluates every Strudel pattern headlessly before answering: the tool result reports layers, events per cycle, tempo, and which sound names are registered (or a syntax error with line:column), so terminal clients get real diagnostics too. (The hosted worker can't — Cloudflare forbids dynamic code generation — and says so.)
Record & download — capture live audio and export as WAV
analyze-harmony — chord detection, key detection, progressions, chord scales; answers in both ABC chord symbols and Strudel chord()/note() form
convert-abc-to-strudel — take a scored melody into the live REPL: bars become mini-notation groups, durations become @ weights, chord symbols become a chord().voicing() line
search-music-docs — semantic search over strudel.cc and ABCJS documentation
Click-to-play links — in clients that can't render the inline widget (terminals, CLIs), both play tools return a hosted URL that actually plays. Short pieces travel in the link itself; longer ones are stored for 30 days
Local Install (Optional)
The remote URL above works without any local setup. If you prefer running locally (offline use, lower latency), install via npm:
Clients that support ext-apps render the interactive UI inline automatically (auto mode). For clients that don't (Cherry Studio, CLI environments), use --render-mode:
Clients without a widget also get a click-to-play link in the tool result, served by the hosted worker — no local render mode needed.
HTTP mode (--host, --allow-origin)
Without --stdio the server listens over Streamable HTTP. That endpoint is unauthenticated, so it binds 127.0.0.1:3001 by default and only accepts browser requests from loopback origins.
Flag
Default
Purpose
--host ADDR
127.0.0.1
Bind address. A non-loopback value prints a warning and turns off the SDK's DNS-rebinding protection — put a proxy that authenticates in front of it
--allow-origin ORIGIN
loopback pages only
Extra CORS origins (comma-separated, repeatable; * opts back into a wildcard)
PORT (env)
3001
Listen port
Tools
Tool
Description
Parameters
play-sheet-music
ABC notation → visual sheet music + multi-instrument audio
Name a chord, guess the key, get a progression or chord scale — in ABC and Strudel spellings
task, notes?, chords?, key?, romanNumerals?
convert-abc-to-strudel
Turn a scored ABC melody into a Strudel mini-notation pattern
abcNotation, voice?, sound?
visuals — none, pianoroll, punchcard, scope, spectrum, hydra-kaleid, hydra-pulse, hydra-wash, hydra-feed.
theme — any of the 39 schemes the Strudel REPL ships (strudelTheme, nord, sonicPink, teletext, gruvboxDark, githubLight, …).
style — rock, jazz, bossa, waltz, march, reggae, folk, classical.
Prompts
Slash-command / menu entry points, in clients that surface MCP prompts:
Prompt
What it does
compose-beat
Generate + play a Strudel pattern in a genre (args: genre, mood?)
harmonize-melody
Add chords/accompaniment to an ABC melody and play it (args: melody, style?)
arrange-tune
Turn a melody/idea into a multi-voice arrangement (args: tune, instrumentation?)
0.5.6 — September 14, 2026
Dependency and compatibility maintenance: audited dependency locks, ext-apps v2
widgets, the SDK v1-compatible worker adapter, and validated worker startup.
The seven tools, music features and UI controls retain their existing behavior.
Builds now synchronize the MCP Registry metadata with the package version, and
publishing waits for the npm package to propagate before registry registration.
Development
Use Bun 1.4.2 and Node 24 for development and CI. Dependency updates use the Bun
ecosystem so both package manifests and lockfiles stay consistent. The server
retains SDK v1 and the worker uses Agents' legacy MCP handler; widgets use
ext-apps v2. CI checks both locks for vulnerabilities and exercises the real
worker HTTP transport as well as the local/worker parity suite. The worker entry
module exports only its fetch handler; test helpers stay in the implementation
module because workerd rejects constants as runtime entry points.
bash
bun install
bun run dev # watch + serve (hot reload)
bun run build # production build (widgets must be built before the tests)
bun run test# run tests
dev/ is a local ext-apps host harness for driving the widgets outside a real client — see dev/README.md.
Live coding is powered by Strudel — canonical repo at codeberg.org/uzu/strudel (the project moved off GitHub, so the GitHub mirror can be stale). Notation and playback use abcjs; shader backgrounds use hydra-synth.