MCP Music Studio

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:

https://music-studio.linxule.com/mcp

Claude Desktop / claude.ai: Settings → Connectors → Add Connector → paste the URL above → done.

Claude Code:

claude mcp add --transport http music-studio https://music-studio.linxule.com/mcp

That's it — ask Claude to play a song or create a beat.

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What You Get

Scored Composition (ABC Notation)

Write sheet music → see it rendered → hear it played with multi-instrument audio.

• 8 style presets — rock, jazz, bossa, waltz, march, reggae, folk, classical — one parameter adds drums + bass + chord accompaniment
• 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. When the score picks its own instrument (%%MIDI program), the Instrument menu shows it, and choosing another really swaps the melody's instrument
• Visual sheet music — notes highlight as they play (on the swung beat when swing is set), and the score scrolls to keep the playing line in view. Scroll by hand at any time and the follow steps aside
• 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. Changing instrument, sound, style or tempo keeps your Loop and tempo settings and never starts a paused tune
• Notes that ring out — each note fades naturally instead of stopping dead, and a light Room echo (on by default, one toolbar toggle) gives the synth a space to play in. WAV downloads and share links sound the same
• 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
• get-music-guide — 7 reference topics (instruments, drums, ABC syntax, arrangements, genres, styles, MIDI directives)

Live Performance (Strudel)

Write code → hear it play → edit in a live REPL.

• TidalCycles mini-notation in JavaScript
• 71 drum machine banks + 128 GM instruments + 128 VCSL orchestral/world/percussion samples + built-in synths
• 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() / .spiral() / .pitchwheel() to animate behind the code (native strudel.cc overlay)
• Layered and hand-drawn visuals — give each visual its own canvas with ctx: getDrawContext('name') so several play at once, or draw anything yourself with .onPaint((ctx, time, haps) => …), reacting to the notes and the sound
• Inline visuals and sliders — ._pianoroll(), ._scope() and friends draw under their own line of code; slider(value, min, max) puts a knob in the code to drag while it plays
• Hydra shader backgrounds — await initHydra() + Hydra code for fully custom, music-synced WebGL visuals. H(pattern) locks a shader parameter to the sequence — notes arrive as MIDI numbers, so a melody can steer a shader — and 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 (recordings longer than about two minutes download in the recorder's own compressed format, so the file stays a sensible size)
• get-strudel-guide — 9 reference topics (mini-notation, sounds, effects, patterns, genres, tips, visuals, hydra, advanced)

Shared

• 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 — short pieces include a self-contained browser link; the music is encoded in the URL, not encrypted. Playback never stores a composition in the share database. For longer pieces, use the inline widget, a local browser render, or explicitly ask for a stored share
• Explicit sharing — create-share-link uploads a score or pattern for 30 days. Anyone with the link can view and play it; creating the same share again refreshes its expiry. Standalone Strudel pages wait for Play or an intentional editor evaluation shortcut, including older autoplay links
• Widgets that fit the host — both widgets size themselves from the host's container (inline, fixed or fullscreen), respect safe-area insets and the host's fonts, and never pan sideways on a phone. If the browser holds audio back until a tap, the widget says "Tap Play to start audio" instead of pretending to play. Scrolling past a widget never starts it, and a tune autoplays once — not again every time the host rebuilds the widget

---

Local Install (Optional)

The remote URL above works without any local setup. If you prefer running locally (offline use, lower latency), install via npm:

CLI One-Liners

# Claude Code
claude mcp add music-studio -- npx -y mcp-music-studio --stdio

# Codex CLI
codex mcp add -- npx -y mcp-music-studio --stdio

# Gemini CLI
gemini mcp add -- npx -y mcp-music-studio --stdio

# OpenCode
opencode mcp add music-studio -- npx -y mcp-music-studio --stdio

JSON Config (Claude Desktop, Cursor, Windsurf, etc.)

Claude Desktop — edit config file

OS	Path
macOS	~/Library/Application Support/Claude/claude_desktop_config.json
Windows	%APPDATA%\Claude\claude_desktop_config.json
Linux	~/.config/Claude/claude_desktop_config.json

{
  "mcpServers": {
    "music-studio": {
      "command": "npx",
      "args": ["-y", "mcp-music-studio", "--stdio"]
    }
  }
}

VS Code / Trae / PearAI

Add to .vscode/mcp.json — note: uses "servers" not "mcpServers":

{
  "servers": {
    "music-studio": {
      "command": "npx",
      "args": ["-y", "mcp-music-studio", "--stdio"]
    }
  }
}

Cursor

Add to ~/.cursor/mcp.json:

{
  "mcpServers": {
    "music-studio": {
      "command": "npx",
      "args": ["-y", "mcp-music-studio", "--stdio"]
    }
  }
}

Windsurf

Add to ~/.codeium/windsurf/mcp_config.json:

{
  "mcpServers": {
    "music-studio": {
      "command": "npx",
      "args": ["-y", "mcp-music-studio", "--stdio"]
    }
  }
}

Windows

On Windows, npx is a .cmd file and requires a shell wrapper:

{
  "mcpServers": {
    "music-studio": {
      "command": "cmd",
      "args": ["/c", "npx", "-y", "mcp-music-studio", "--stdio"]
    }
  }
}

Render modes (for non-ext-apps clients)

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:

Mode	Behavior
auto (default)	Inline UI for Claude Desktop, VS Code
browser	Saves HTML and opens in system browser
html	Returns HTML as embedded resource

{
  "mcpServers": {
    "music-studio": {
      "command": "npx",
      "args": ["-y", "mcp-music-studio", "--stdio", "--render-mode", "browser"]
    }
  }
}

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	abcNotation, title?, instrument?, style?, tempo? (40–240), swing? (0–75), drumIntro? (0–8), transpose? (−12–12)
play-live-pattern	Strudel code → live-coded patterns with synthesis + effects	code, title?, bpm? (40–300), autoplay?, visuals?, theme?
get-music-guide	ABC reference (7 topics: instruments, drums, syntax, genres...)	topic
get-strudel-guide	Strudel reference (9 topics: sounds, effects, visuals, hydra, genres...)	topic
search-music-docs	Semantic search over strudel.cc and ABCJS docs	query, library (strudel | abcjs)
analyze-harmony	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?
create-share-link	Explicitly store a piece and return a 30-day link accessible to anyone holding it	kind (score or play), matching score or pattern object with the corresponding play tool's arguments

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?)

0.6.0 — September 26, 2026

The canonical endpoint is now https://music-studio.linxule.com/mcp. Existing mcp-music-studio.linxule.workers.dev connections and shared links continue to work.

Playback no longer stores compositions automatically. Use the new create-share-link tool when you explicitly want to upload a composition for a 30-day link. The hosted privacy policy explains storage, retention, and external providers. Standalone Strudel pages start only after an intentional Play action.

This release corrects ABC pitch/drum guidance and harmony error reporting, adds real browser audio and export checks to CI and publishing, and updates development dependencies. The combined application is now AGPL-3.0-or-later, with the original MIT notices preserved and editable source/build inputs included in the npm package. Earlier releases retain their original notices. See SOURCE.md.

0.5.14 — September 25, 2026

The local server's pattern check rejected every Strudel pattern written with $: blocks — Strudel's everyday way to run several patterns — as "failed to evaluate" while the widget played it fine. It now follows the REPL: blocks play stacked, _$: mutes, S$: solos, and the result counts the blocks as layers. A pattern ending in a Hydra line no longer hangs the check. The release film, Rest, was made with the studio itself — the score drawn by abcjs, the song a single Strudel file with its arrangement in the code — and the tools that shot it are in scripts/showcase/film/. 0.5.14

0.5.13 — September 25, 2026

The sheet widget's Room button showed as a blank blue box while on: its label was drawn in the same blue as its pressed background (0.5.10–0.5.12). It now reads like the Edit toggle, white on blue. 0.5.13

0.5.12 — September 25, 2026

Tested on a phone, then opened up. Scrolling a conversation no longer starts music, and a tune autoplays once per tool call instead of on every rebuild; Strudel code wraps. Sheet music rings out — a softer note release and a light Room echo, in the widget, WAV downloads and share links. Strudel visuals gain layers, hand-drawn onPaint art, inline visuals and sliders, and pitch-driven Hydra shaders, and share links now match the widget. Details: 0.5.9 · 0.5.10 · 0.5.11 · 0.5.12.

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.

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
bunx playwright install chromium  # one-time browser install
bun run test:audio   # real browser audio, visuals, WAV and MIDI exports
bun run test:package # check source and license contents of the npm package

dev/ is a local ext-apps host harness for driving the widgets outside a real client — see dev/README.md.

The browser audio gate starts that harness automatically and tests the built widgets using Chromium and the real MCP Apps bridge. It measures rendered audio samples, checks silence after stopping, and inspects exported WAV/MIDI bytes. It needs network access to the pinned Strudel runtime and ABC soundfont provider. CI and tag publishing both run it; failed runs retain traces and screenshots. The harness does not enforce a client's CSP or reproduce every client's sandbox and audio policy.

Privacy policy

Read the hosted privacy policy (source) for composition sharing, analytics, browser storage, Context7 search, external sample/script providers, retention, and contact details. Playback and persistent sharing are separate operations. Short browser links contain the composition itself; do not include sensitive information in them.

For example, explicitly creating a stored pattern link uses:

{
  "kind": "play",
  "pattern": { "code": "s(\"bd sd\")", "title": "My beat" }
}

Call create-share-link only when the user asks to share or store the piece. It also uploads to the hosted service when called through the local server.

Attribution

Forked from the Sheet Music Server example from MCP ext-apps by Anthropic, licensed under MIT.

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.

License

The combined application is licensed under AGPL-3.0-or-later. The original MIT notices and grants are preserved in LICENSES/MIT.txt. This change does not revoke the licenses of earlier releases. See SOURCE.md for corresponding source and build instructions, and THIRD_PARTY_NOTICES.md for dependency and audio-asset licensing. Music you create is not automatically licensed under the application’s software license.