Music Theory MCP 🎵

Give your AI coding assistant musical knowledge.

Scales, chords, progressions, key detection, genre-aware composition intelligence, and rhythm patterns.

4 free tools work instantly. 9 pro tools unlock with a free CODEDSWITCH_API_KEY (50 calls/day). Unlimited plans at codedswitch.com/pricing.

Works with Claude Code, Cursor, Windsurf, and any MCP-compatible IDE.

Companion to WebEar — WebEar gives your AI ears, Music Theory MCP gives it a brain for music.

13 Tools

Free (no key needed)

| Tool | Description | |------|-------------| | get_scale | Notes & intervals for 20+ scale types (major, minor, pentatonic, blues, dorian, etc.) | | get_chord | Notes for 22+ chord types (triads, 7ths, 9ths, sus, aug, dim, etc.) | | transpose_note | Shift a note by semitones | | get_interval | Interval between two notes |

Pro (requires CODEDSWITCH_API_KEY)

| Tool | Description | |------|-------------| | identify_chord | Name a chord from its notes | | detect_key | Detect the key from observed notes with confidence scores | | resolve_progression | Roman numerals → actual chords in any key | | suggest_next_chord | "What chord comes next?" with voice leading intelligence | | get_diatonic_chords | All 7 chords in any key | | get_genre_profile | Full genre intel: progressions, instruments, BPM, mood, swing | | suggest_genre | Match genre from BPM / key / mood / scale | | get_genre_rhythms | Drum patterns (kick/snare/hat step arrays) per genre | | transpose_progression | Shift an entire chord progression |

Get a free key at codedswitch.com/developer — 50 pro calls/day included.

11 Genres

Trap · Boom Bap · Drill · Lo-Fi Hip Hop · R&B · Pop · Afrobeats · Reggaeton · Jazz · EDM · Gospel

Each genre includes: chord progressions, recommended scales, BPM range, instruments, rhythmic feel, swing amount, common keys, and mood descriptors.

Quick Start

Option 1: npx (no install)

npx music-theory-mcp

Option 2: Global install

npm install -g music-theory-mcp

IDE Configuration

Claude Code

Add to .mcp.json:

{
  "mcpServers": {
    "music-theory": {
      "command": "npx",
      "args": ["music-theory-mcp"],
      "env": { "CODEDSWITCH_API_KEY": "csk_your_key_here" }
    }
  }
}

Cursor

Add to .cursor/mcp.json:

{
  "mcpServers": {
    "music-theory": {
      "command": "npx",
      "args": ["music-theory-mcp"],
      "env": { "CODEDSWITCH_API_KEY": "csk_your_key_here" }
    }
  }
}

Windsurf

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

{
  "mcpServers": {
    "music-theory": {
      "command": "npx",
      "args": ["music-theory-mcp"],
      "env": { "CODEDSWITCH_API_KEY": "csk_your_key_here" }
    }
  }
}

Omit the env block to use free tools only.

Example Usage

Once configured, your AI assistant can use the tools naturally:

"What chords are in the key of F minor?"

→ get_diatonic_chords({ key: "F", mode: "minor" })
→ Fm, Gdim, Ab, Bbm, Cm, Db, Eb

"Give me a trap beat in C minor"

→ get_genre_profile({ genre: "trap" })
→ Progressions: i-iv-VI-v, scales: minor/phrygian, BPM: 130-170
→ get_genre_rhythms({ genre: "trap" })
→ Kick/snare/hat patterns ready for a sequencer

"What key is this melody in? C, D, E, F#, G, A, B"

→ detect_key({ notes: ["C", "D", "E", "F#", "G", "A", "B"] })
→ G major (100% confidence)

"I'm on a V chord in Bb major, what should come next?"

→ suggest_next_chord({ current_numeral: "V", key: "Bb", mode: "major" })
→ I (Bb), vi (Gm), IV (Eb) — ranked by voice leading tendency

Use Cases

• AI music apps — give your AI composer harmonic intelligence
• Beat makers & DAWs — auto-suggest progressions, detect keys, genre-match rhythms
• Music education — interactive scale/chord/theory lookup
• Songwriting tools — intelligent chord suggestions and key detection
• MIDI processors — transpose, identify, and analyze musical content
• Any AI agent — add musical reasoning to any MCP-compatible agent

Pairs With WebEar

| | WebEar | Music Theory MCP | |---|--------|-----------------| | What | Captures & analyzes live audio | Reasons about music theory | | Analogy | Ears | Brain | | API keys | Required (CodedSwitch) | Free tier: none / Pro: CodedSwitch key | | Together | Hear what's playing → analyze if it's harmonically correct → suggest fixes |

Built by CodedSwitch

Part of the CodedSwitch Studio ecosystem — AI-powered music creation.

License

MIT