MuseScore MCP Server

A Model Context Protocol (MCP) server that provides programmatic control over MuseScore, via a WebSocket-based plugin system. This allows AI assistants like Claude to compose music, add lyrics, navigate scores, and control MuseScore directly.

Prerequisites

• MuseScore 3.x or 4.x
• Python 3.8+
• Claude Desktop or compatible MCP client

Setup

1. Install the MuseScore Plugin

First, save the QML plugin code to your MuseScore plugins directory:

macOS: ~/Documents/MuseScore4/Plugins/musescore-mcp-websocket.qml
Windows: %USERPROFILE%\Documents\MuseScore4\Plugins\musescore-mcp-websocket.qml
Linux: ~/Documents/MuseScore4/Plugins/musescore-mcp-websocket.qml

2. Enable the Plugin in MuseScore

1. Open MuseScore
2. Go to Plugins → Plugin Manager
3. Find "MuseScore API Server" and check the box to enable it
4. Click OK

3. Setup Python Environment

git clone <your-repo>
cd mcp-agents-demo
python -m venv .venv
source .venv/bin/activate  # On Windows: .venv\Scripts\activate
pip install fastmcp websockets

4. Configure Claude Desktop

Add to your Claude Desktop configuration file:

macOS: ~/Library/Application Support/Claude/claude_desktop_config.json
Windows: %APPDATA%\Claude\claude_desktop_config.json

{
  "mcpServers": {
    "musescore": {
      "command": "/path/to/your/project/.venv/bin/python",
      "args": [
        "/path/to/your/project/server.py"
      ]
    }
  }
}

Note: Update the paths to match your actual project location.

Running the System

Order of Operations

1. Start MuseScore first with a score open
2. Run the MuseScore plugin: Go to Plugins → MuseScore API Server
   • You should see console output: "Starting MuseScore API Server on port 8765"
3. Then start the Python MCP server or restart Claude Desktop

[insert screenshot of different functionality, harmonisation, melodywriting, as zoomed in GIFs]

Development and Testing

For development, use the MCP development tools:

# Install MCP dev tools
pip install mcp

# Test your server
mcp dev server.py

# Check connection status
mcp dev server.py --inspect

Viewing Console Output

To see MuseScore plugin console output, run MuseScore from terminal:

macOS:

/Applications/MuseScore\ 4.app/Contents/MacOS/mscore

Windows:

cd "C:\Program Files\MuseScore 4\bin"
MuseScore.exe

Linux:

musescore4

Features

This MCP server provides comprehensive MuseScore control. 🌟 NEW in this fork: Built-in automatic, flawless multi-voice Polyphony & Temporal layout mapping to LilyPond!

Navigation & Cursor Control

• get_cursor_info() - Get current cursor position and selection info
• go_to_measure(measure) - Navigate to specific measure
• go_to_beginning_of_score() / go_to_final_measure() - Navigate to start/end
• next_element() / prev_element() - Move cursor element by element
• next_staff() / prev_staff() - Move between staves
• select_current_measure() - Select entire current measure
• select_custom_range(start_tick, end_tick, start_staff, end_staff) - 🌟 Slicing tool to extract cross-measure, multi-staff phrasing perfectly!

Polyphony & LilyPond Integration

• Temporal Rhythm Padding: Voices with gaps or rests automatically receive LilyPond spacer sequences (s4.) to hold their mathematical place accurately.
• Concurrent Voice Rendering: Full 4-voice (\voiceOne, \voiceTwo, etc.) arrays correctly structured and sharded per staff for advanced Agent processing.

Note & Rest Creation

• add_note(pitch, duration, advance_cursor_after_action) - Add notes with MIDI pitch
• add_rest(duration, advance_cursor_after_action) - Add rests
• add_tuplet(duration, ratio, advance_cursor_after_action) - Add tuplets (triplets, etc.)

Measure Management

• insert_measure() - Insert measure at current position
• append_measure(count) - Add measures to end of score
• delete_selection(measure) - Delete current selection or specific measure

Lyrics & Text

• add_lyrics_to_current_note(text) - Add lyrics to current note
• add_lyrics(lyrics_list) - Batch add lyrics to multiple notes
• set_title(title) - Set score title

Score Information

• get_score() - Get complete score analysis and structure
• ping_musescore() - Test connection to MuseScore
• connect_to_musescore() - Establish WebSocket connection

Utilities

• undo() - Undo last action
• set_time_signature(numerator, denominator) - Change time signature
• processSequence(sequence) - Execute multiple commands in batch

Sample Music

Check out the /examples folder for sample MuseScore files demonstrating various musical styles:

• Asian Instrumental - Traditional Asian-inspired instrumental piece
• String Quartet - Classical string quartet arrangement

Each example includes:

• .mscz - MuseScore file (editable)
• .pdf - Sheet music
• .mp3 - Audio preview

Usage Examples

Creating a Simple Melody

# Set up the score
await set_title("My First Song")
await go_to_beginning_of_score()

# Add notes (MIDI pitch: 60=C, 62=D, 64=E, etc.)
await add_note(60, {"numerator": 1, "denominator": 4}, True)  # Quarter note C
await add_note(64, {"numerator": 1, "denominator": 4}, True)  # Quarter note E
await add_note(67, {"numerator": 1, "denominator": 4}, True)  # Quarter note G
await add_note(72, {"numerator": 1, "denominator": 2}, True)  # Half note C

# Add lyrics
await go_to_beginning_of_score()
await add_lyrics_to_current_note("Do")
await next_element()
await add_lyrics_to_current_note("Mi")
await next_element()
await add_lyrics_to_current_note("Sol")
await next_element()
await add_lyrics_to_current_note("Do")

Batch Operations

# Add multiple lyrics at once
await add_lyrics(["Twin-", "kle", "twin-", "kle", "lit-", "tle", "star"])

# Use sequence processing for complex operations
sequence = [
    {"action": "goToBeginningOfScore", "params": {}},
    {"action": "addNote", "params": {"pitch": 60, "duration": {"numerator": 1, "denominator": 4}, "advanceCursorAfterAction": True}},
    {"action": "addNote", "params": {"pitch": 64, "duration": {"numerator": 1, "denominator": 4}, "advanceCursorAfterAction": True}},
    {"action": "addRest", "params": {"duration": {"numerator": 1, "denominator": 4}, "advanceCursorAfterAction": True}}
]
await processSequence(sequence)

Star History

Troubleshooting

Connection Issues

• "Not connected to MuseScore":
  • Ensure MuseScore is running with a score open
  • Run the MuseScore plugin (Plugins → MuseScore API Server)
  • Check that port 8765 isn't blocked by firewall

Plugin Issues

• Plugin not appearing: Check the .qml file is in the correct plugins directory
• Plugin won't enable: Restart MuseScore after placing the plugin file
• No console output: Run MuseScore from terminal to see debug messages

Python Server Issues

• "No server object found": The server object must be named mcp, server, or app at module level
• WebSocket errors: Make sure MuseScore plugin is running before starting Python server
• Connection timeout: The MuseScore plugin must be actively running, not just enabled

API Limitations

• Lyrics: Only first verse supported in MuseScore 3.x plugin API
• Title setting: Uses multiple fallback methods due to frame access limitations
• Selection persistence: Some operations may affect current selection

File Structure

mcp-agents-demo/
├── .venv/
├── server.py                           # Python MCP server entry point
├── musescore-mcp-websocket.qml         # MuseScore plugin
├── requirements.txt
├── README.md
└── src/                                # Source code modules
    ├── __init__.py
    ├── client/                         # WebSocket client functionality
    │   ├── __init__.py
    │   └── websocket_client.py
    ├── tools/                          # MCP tool implementations
    │   ├── __init__.py
    │   ├── connection.py               # Connection management tools
    │   ├── navigation.py               # Score navigation tools
    │   ├── notes_measures.py           # Note and measure manipulation
    │   ├── sequences.py                # Batch operation tools
    │   ├── staff_instruments.py        # Staff and instrument tools
    │   └── time_tempo.py               # Timing and tempo tools
    └── types/                          # Type definitions
        ├── __init__.py
        └── action_types.py             # WebSocket action type definitions

MIDI Pitch Reference

Common MIDI pitch values for reference:

• Middle C: 60
• C Major Scale: 60, 62, 64, 65, 67, 69, 71, 72
• Chromatic: C=60, C#=61, D=62, D#=63, E=64, F=65, F#=66, G=67, G#=68, A=69, A#=70, B=71

Duration Reference

Duration format: {"numerator": int, "denominator": int}

• Whole note: {"numerator": 1, "denominator": 1}
• Half note: {"numerator": 1, "denominator": 2}
• Quarter note: {"numerator": 1, "denominator": 4}
• Eighth note: {"numerator": 1, "denominator": 8}
• Dotted quarter: {"numerator": 3, "denominator": 8}