live-coding-music-mcp

🎵 MCP server for AI-assisted live-coding music via strudel.cc

Unofficial fan project. Not affiliated with, or endorsed by, the Strudel project. This adapter exists to make live-coding music accessible to beginners who want to try pattern-based music without learning the whole ecosystem first.

Status: Beta | 77% test coverage | Published to npm | Actively developed

A Model Context Protocol (MCP) server that drives Strudel.cc from Claude for AI-assisted live-coding music, pattern generation, and algorithmic composition.

Current State: Beta. The core workflow (init → generate → write → play → analyze) works reliably with real audio output and has 1470 passing tests covering 77% of statements. CI is hardened with OpenSSF Scorecard, SHA-pinned actions, CODEOWNERS, and Dependabot. Known coverage gaps exist (notably AudioCaptureService at 33% and AudioAnalyzer branch coverage at 48%) — see open issues for the full list.

What "Beta" means here:

• Tool schemas are stable within minor versions; breaking changes require a major bump
• Single-browser-session limitation (multi-session tracked in #108)
• Upstream @strudel/* dependencies pinned to known-good versions; Dependabot bumps gated on CI
• Expect hands-on iteration for non-standard patterns — report rough edges, they get fixed

• Features
• Installation
• Quick Reference
• Quick Start
• Available Tools
• Usage Examples
• Architecture
• Advanced Usage
• Configuration
• Security
• Troubleshooting
• Development
• Contributing

• 65 MCP Tools: Comprehensive suite for music creation and manipulation
• Real Browser Automation: Direct control of Strudel.cc through Playwright
• Live Audio Analysis: Real-time frequency analysis via Web Audio API
• Pattern Generation: AI-powered creation across 8+ music genres
• Music Theory Engine: Scales, chords, progressions, euclidean rhythms
• Session Management: Save, load, undo/redo with pattern storage

• ✅ Test Suite: Comprehensive test coverage across unit, integration, and validation tests
• ✅ Code Coverage: Actively tracked via CI
• ✅ Browser Integration: Works with live Strudel.cc website
• ✅ Audio Analysis: Real-time FFT analysis functional
• ✅ Pattern Generation: Core music generation features working
• ✅ OIDC Publishing: Secure npm publishing with provenance attestation

Not Production-Ready: This is experimental software under active development. Use for exploration and experimentation. Expect breaking changes, bugs, and incomplete features. See CONTRIBUTING.md to help improve it.

Explore 17 curated example patterns across 10 genres in patterns/examples/:

• Techno: Hard techno, minimal techno
• House: Deep house, tech house
• Drum & Bass: Liquid, neurofunk
• Ambient: Dark ambient, drone
• Trap: Modern trap, cloud trap
• Jungle: Classic jungle, ragga jungle
• Jazz: Bebop, modal jazz
• Intelligent DnB: Atmospheric, liquid, LTJ Bukem style
• Trip Hop: Portishead, Massive Attack, Flying Lotus style
• Boom Bap: DJ Premier, Alchemist, golden era hip hop

Each example includes pattern code, BPM, key, and description. See patterns/examples/README.md for details.

This project was renamed from @williamzujkowski/strudel-mcp-server to @williamzujkowski/live-coding-music-mcp to make the unofficial fan-project status unambiguous (see #97). The old package is deprecated on npm.

If you were using the old package:

# Remove old
npm uninstall -g @williamzujkowski/strudel-mcp-server

# Install new
npm install -g @williamzujkowski/live-coding-music-mcp

Update your MCP client config. The bin name changed from strudel-mcp to live-coding-music-mcp:

// BEFORE
{
  "mcpServers": {
    "strudel": { "command": "strudel-mcp" }
  }
}

// AFTER
{
  "mcpServers": {
    "live-coding-music": { "command": "live-coding-music-mcp" }
  }
}

The MCP server's internal identity string also changed from strudel-mcp-enhanced to live-coding-music-mcp. If you have a client that keys on that string (logs, allowlists, permission policies), update it accordingly.

All tool names and schemas are unchanged.

Optional: Docker for containerized deployment.

npm install -g @williamzujkowski/live-coding-music-mcp

# Install browser (required once)
npx playwright install chromium

# Clone repository
git clone https://github.com/williamzujkowski/live-coding-music-mcp.git
cd live-coding-music-mcp

# Install dependencies
npm install

# Install Chromium for browser automation
npx playwright install chromium

# Build the project
npm run build

Common commands for immediate use:

One-shot workflow:

compose with style: "dnb", key: "Am", bpm: 174, auto_play: true

# If installed globally
claude mcp add strudel live-coding-music-mcp

# If built from source
claude mcp add strudel node /path/to/live-coding-music-mcp/dist/index.js

claude chat

Then ask Claude:

• "Initialize Strudel and create a techno beat"
• "Generate a jazz chord progression in F major"
• "Create a drum & bass pattern at 174 BPM"

66 tools across 15 categories:

Auto-generated from source. 66 tools registered.

Create a Simple Beat

You: Initialize Strudel and create a simple techno beat

Claude: [Initializes browser]
        [Generates and writes pattern]
        [Starts playback]

Pattern created:
setcpm(130)
stack(
  s("bd*4"),
  s("~ cp ~ cp"),
  s("hh*8").gain(0.4)
).gain(0.8)

Generate a Bassline

You: Add a techno bassline in C

Claude: [Generates bassline]
        [Appends to current pattern]

Added: note("c2 c2 c2 c2").s("sawtooth").cutoff(800)

Jazz Composition

You: Create a jazz progression in F major with a walking bass

Claude: Generated progression: "Gm7" "C7" "Fmaj7"

Pattern:
stack(
  note("Gm7" "C7" "Fmaj7").struct("1 ~ ~ ~").s("piano"),
  note("g2 c2 f2").s("sine").gain(0.7)
)

Drum & Bass Track

You: Generate a complete drum & bass track at 174 BPM

Claude: [Creates multi-layer pattern with drums, bass, and pads]

// dnb pattern in C at 174 BPM
setcpm(174)
stack(
  // Drums
  s("bd ~ ~ [bd bd] ~ ~ bd ~, ~ ~ cp ~ ~ cp ~ ~").fast(2),

  // Bass
  note("c1 ~ ~ c2 ~ c1 ~ ~").s("square").cutoff(400),

  // Pads (atmospheric)
  note("c3 eb3 g3 bb3").s("sawtooth")
    .attack(2).release(4).room(0.8).gain(0.6)
)

Live Audio Analysis

You: Analyze what's playing and show me the frequency breakdown

Claude: Audio Analysis Results:
{
  "connected": true,
  "features": {
    "average": 78.5,
    "peak": 180,
    "peakFrequency": 120,
    "bass": 145,
    "mid": 82,
    "treble": 45,
    "isPlaying": true,
    "brightness": "balanced"
  }
}

Strong bass presence detected - typical for techno/house patterns.

Pattern Variations

You: Create a glitchy variation of the current pattern

Claude: [Applies glitch transformation]

Added: .sometimes(x => x.chop(8).rev).rarely(x => x.speed(-1))

Layered Ambient Track

You: Create an ambient soundscape with multiple layers

Claude: [Generates complex multi-layer pattern]

setcpm(90)
stack(
  // Deep bass drone
  note("c1").s("sine").attack(4).release(8).gain(0.5),

  // Texture pad
  note("c3 eb3 g3").s("sawtooth")
    .attack(2).release(6).room(0.9).gain(0.4),

  // Sparse percussion
  s("bd ~ ~ ~, ~ ~ ~ hh:8").room(0.9).gain(0.3),

  // Melodic sparkles
  note("c5 g5 eb5 bb5").struct("~ 1 ~ 1 ~ ~ 1 ~")
    .s("triangle").delay(0.5).room(0.8).gain(0.3)
)

Save and Load Patterns

You: Save this pattern as "techno-groove-1" with tags "techno" and "experimental"

Claude: Pattern saved as "techno-groove-1"

---

You: List all my techno patterns

Claude: Saved patterns with tag "techno":
• techno-groove-1 [techno, experimental] - 2025-10-23T19:30:00.000Z
• acid-bassline [techno, acid] - 2025-10-23T18:15:00.000Z

---

You: Load "acid-bassline"

Claude: Loaded pattern "acid-bassline"
[Pattern written to editor]

Generate Euclidean Rhythms

You: Create a 5/8 euclidean rhythm with kick drum

Claude: Generated Euclidean rhythm (5/8)

Pattern: s("bd").struct("1 ~ 1 ~ 1 1 ~ 1")

Complex Polyrhythms

You: Generate a polyrhythm with kick (4/16), snare (7/16), and hi-hat (3/16)

Claude: Generated polyrhythm

stack(
  s("bd").euclid(4, 16),
  s("cp").euclid(7, 16),
  s("hh").euclid(3, 16)
)

AI-Assisted Composition

You: Analyze the mood of my current pattern and suggest complementary elements

Claude: [Analyzes pattern structure and audio features]

Your pattern has:
- Energetic rhythm (130 BPM)
- Strong bass presence
- Minimal melodic content

Suggestions:
1. Add arpeggiated synth for movement
2. Include occasional breaks/fills
3. Layer atmospheric pad for depth

Would you like me to add any of these?

You: Add an arpeggiated synth in C minor

Claude: [Generates and adds]

note("c4 eb4 g4 bb4 c5").struct("1 1 1 1 1 1 1 1")
  .s("triangle").delay(0.25).room(0.3).gain(0.5)

All tools have been tested with real Strudel.cc interaction:

# Run integration tests
npm run test:integration

# Run browser tests
node tests/strudel-integration.js

# Run npm test to see current pass/fail/skip counts

{
  "headless": false,        // Set true for background operation
  "strudel_url": "https://strudel.cc/",
  "patterns_dir": "./patterns",
  "audio_analysis": {
    "fft_size": 2048,
    "smoothing": 0.8
  }
}

The Strudel MCP Server is built with a modular architecture that separates concerns and enables robust music generation:

┌─────────────────────────────────────────────────────────────┐
│                       Claude AI                              │
│                  (MCP Client)                                │
└───────────────────────┬─────────────────────────────────────┘
                        │ MCP Protocol (stdio)
                        │
┌───────────────────────▼─────────────────────────────────────┐
│              StrudelMCPServer                          │
│  ┌────────────────────────────────────────────────────────┐ │
│  │  Tool Request Handler                                  │ │
│  │  - Validates inputs                                    │ │
│  │  - Routes to appropriate service                       │ │
│  │  - Handles errors gracefully                           │ │
│  └────────────────────────────────────────────────────────┘ │
└───────┬────────────┬────────────┬───────────┬──────────────┘
        │            │            │           │
   ┌────▼────┐  ┌───▼────┐  ┌───▼────┐  ┌──▼──────┐
   │ Strudel │  │ Music  │  │Pattern │  │ Pattern │
   │Controller│  │ Theory │  │Generator│  │  Store  │
   └────┬────┘  └────────┘  └────────┘  └─────────┘
        │
   ┌────▼────────────────────────────┐
   │   Playwright Browser            │
   │  ┌──────────────────────────┐   │
   │  │   Strudel.cc Website     │   │
   │  │  ┌────────────────────┐  │   │
   │  │  │  CodeMirror Editor │  │   │
   │  │  └────────────────────┘  │   │
   │  │  ┌────────────────────┐  │   │
   │  │  │  Audio Context     │  │   │
   │  │  │  + Web Audio API   │  │   │
   │  │  └────────┬───────────┘  │   │
   │  └───────────┼──────────────┘   │
   └──────────────┼──────────────────┘
                  │
          ┌───────▼────────┐
          │ Audio Analyzer │
          │  - FFT Analysis│
          │  - Frequency   │
          │  - Spectral    │
          └────────────────┘

Main MCP server implementation handling:

• 65 Tool Definitions: Complete API surface for music control
• Request Routing: Directs tool calls to appropriate handlers
• State Management: Tracks initialization, undo/redo stacks, pattern cache
• Error Handling: Graceful degradation and informative error messages
• Lazy Initialization: Browser starts only when needed

Key Features:

- Pattern caching before browser init
- Undo/redo stack management
- Session history tracking
- Generated pattern storage
- Safe fallback mechanisms

Browser automation layer using Playwright:

• Browser Management: Chromium instance lifecycle
• Editor Control: CodeMirror manipulation via DOM
• Playback Control: Keyboard shortcuts for play/stop
• Performance Optimizations:
  • Editor content caching (100ms TTL)
  • Direct CodeMirror API access
  • Resource blocking (images, fonts)
  • Fast DOM content loading

// Example: Optimized pattern writing
async writePattern(pattern: string) {
  await this.page.evaluate((newPattern) => {
    const editor = document.querySelector('.cm-content');
    const view = editor.__view;
    view.dispatch({
      changes: { from: 0, to: view.state.doc.length, insert: newPattern }
    });
  }, pattern);
}

Real-time audio analysis via Web Audio API injection:

• FFT Analysis: 1024-point FFT for spectral data
• Frequency Bands: Bass, low-mid, mid, high-mid, treble
• Analysis Caching: 50ms TTL for performance
• Features Extracted:
  • Average amplitude
  • Peak frequency
  • Spectral centroid
  • Playing state detection
  • Frequency distribution

Features provided:
- average: Overall amplitude (0-255)
- peak: Maximum amplitude
- peakFrequency: Dominant frequency in Hz
- bass/mid/treble: Band-specific amplitudes
- brightness: Timbral classification
- isPlaying: Boolean playback state

Music theory engine providing:

• 15+ Scales: Major, minor, modes, pentatonic, blues, whole-tone
• Chord Progressions: Pop, jazz, blues, rock, folk, EDM
• Euclidean Rhythms: Mathematical rhythm generation
• Arpeggio Generation: Multiple patterns (up, down, random)
• Note Transposition: Semitone-based pitch shifting

Supported scales:

major, minor, dorian, phrygian, lydian, mixolydian,
aeolian, locrian, pentatonic, blues, chromatic,
wholetone, harmonic_minor, melodic_minor

AI-powered pattern creation:

• Genre Templates: Techno, house, DnB, trap, ambient, jazz, intelligent_dnb, trip_hop, boom_bap
• Drum Patterns: 4 complexity levels per genre
• Basslines: 8 different styles
• Melody Generation: Scale-based with musical intervals
• Variations: Subtle, moderate, extreme, glitch, evolving
• Fills: 1-4 bar drum fills

Example generation:

generateCompletePattern('techno', 'C', 130)
→ Multi-layer pattern with drums, bass, chords, melody

Persistent pattern storage:

• JSON-based: Simple file storage
• Metadata: Name, tags, timestamp, audio features
• Tag Filtering: Organize by genre, mood, project
• Sorted Retrieval: Most recent first

live-coding-music-mcp/
├── src/
│   ├── server/
│   │   └── server.ts                    # MCP server
│   ├── services/
│   │   ├── MusicTheory.ts                # Theory engine
│   │   └── PatternGenerator.ts           # Pattern creation
│   ├── utils/
│   │   └── Logger.ts                     # Logging utility
│   ├── types/
│   │   └── index.ts                      # TypeScript types
│   ├── StrudelController.ts              # Browser automation
│   ├── AudioAnalyzer.ts                  # Audio analysis
│   ├── PatternStore.ts                   # Pattern persistence
│   └── index.ts                          # Entry point
├── tests/
│   ├── browser-test.js                   # Browser integration
│   ├── integration.test.js               # Integration tests
│   ├── manual-test.js                    # Manual testing
│   ├── mcp-tools.test.ts                 # MCP tool tests
│   └── strudel-integration.js            # Full integration
├── patterns/                             # Saved patterns
├── config.json                           # Server configuration
├── package.json                          # Dependencies
└── tsconfig.json                         # TypeScript config

1. Tool Invocation

   Claude → MCP Protocol → StrudelMCPServer
   

2. Pattern Generation (without browser)

   Server → PatternGenerator → MusicTheory → Pattern String
   

3. Pattern Execution (with browser)

   Server → StrudelController → Playwright → Strudel.cc
   

4. Audio Analysis

   Strudel.cc → Web Audio API → AudioAnalyzer → Feature Data
   

1. Caching

   • Editor content: 100ms TTL
   • Audio analysis: 50ms TTL
   • Generated patterns: Until browser init

2. Resource Blocking

   • Images, fonts, media blocked
   • Only load essential JavaScript/CSS

3. Direct API Access

   • CodeMirror view manipulation
   • Keyboard shortcuts over button clicks

4. Lazy Loading

   • Browser starts only when needed
   • Services initialized on-demand

setcpm(130)
stack(
  s("bd*4").gain(0.9),
  s("~ cp ~ cp").room(0.2),
  s("hh*16").gain(0.4).pan(sine.range(-0.5, 0.5)),
  note("c2 c2 eb2 c2").s("sawtooth").cutoff(800)
).swing(0.05)

setcpm(174)
stack(
  s("bd ~ ~ [bd bd] ~ ~ bd ~, ~ ~ sn:3 ~ ~ sn:3 ~ ~").fast(2),
  s("hh*16").gain(0.5),
  note("e1 ~ ~ e2 ~ e1 ~ ~").s("sine:2").lpf(200)
)