AI-Native Generative Music for MIDI Devices

Talk to your studio. Create organic, evolving music through conversation with AI.

SqncR (Sequencer) is an MCP server for generative music. You sit in your IDE, enable the MCP server, tell it about your setup, and it generates music while you code. It works with hardware MIDI devices, Sonic Pi, and VCV Rack 2.

• Code in VS Code on your left monitor
• Chat with Copilot or Claude on your right monitor
• Say "ambient drone, 87 BPM, darker" — your synths start playing
• Keep coding while the music evolves

5 milestones delivered · 586 tests · 30+ MCP tools

# 1. Clone
git clone https://github.com/bradygaster/SqncR.git
cd SqncR

# 2. Install .NET 9 SDK (or later — global.json uses rollForward: latestMajor)
#    https://dotnet.microsoft.com/download

# 3. Install a virtual MIDI driver + a synth
#    loopMIDI  → https://www.tobias-erichsen.de/software/loopmidi.html
#    Sonic Pi  → https://sonic-pi.net/
#    VCV Rack  → https://vcvrack.com/

# 4. Build
dotnet build SqncR.slnx

# 5. Run the MCP server (stdio transport)
dotnet run --project src/SqncR.McpServer

The repo ships .vscode/mcp.json — Copilot discovers SqncR automatically after cloning.

Add to %APPDATA%\Claude\claude_desktop_config.json (Windows) or ~/.config/claude/claude_desktop_config.json (macOS/Linux):

{
  "mcpServers": {
    "sqncr": {
      "command": "dotnet",
      "args": ["run", "--project", "C:/path/to/SqncR/src/SqncR.McpServer"]
    }
  }
}

%%{init: {'theme': 'dark', 'themeVariables': {'primaryColor': '#333', 'primaryTextColor': '#fff', 'lineColor': '#888', 'secondaryColor': '#222', 'tertiaryColor': '#111'}}}%%
flowchart LR
    Client["MCP Client\n(Copilot / Claude)"]
    Server["SqncR.McpServer\n30+ tools"]
    Engine["GenerationEngine\nSqncR.Core"]
    MIDI["Hardware MIDI\n(loopMIDI, synths)"]
    SP["Sonic Pi\n(OSC)"]
    VCV["VCV Rack 2\n(.vcv patches)"]

    Client -- stdio JSON-RPC --> Server
    Server --> Engine
    Engine --> MIDI
    Server --> SP
    Server --> VCV

    style Client fill:#1a1a2e,stroke:#888,color:#fff
    style Server fill:#1a1a2e,stroke:#888,color:#fff
    style Engine fill:#1a1a2e,stroke:#888,color:#fff
    style MIDI fill:#1a1a2e,stroke:#888,color:#fff
    style SP fill:#1a1a2e,stroke:#888,color:#fff
    style VCV fill:#1a1a2e,stroke:#888,color:#fff

📖 Full MCP Integration Guide → — tool signatures, parameters, example conversations, and troubleshooting.

• Multi-channel generation — assign instruments to roles and MIDI channels
• Role-based instruments — Bass, Pad, Lead, Drums, Melody with per-role behavior
• Smooth transitions — tempo and scale changes glide over bars instead of snapping
• Variety engine — conservative, moderate, or adventurous variation levels
• Session persistence — save/load complete generation state (JSON, ~/.sqncr/sessions/)
• Scene presets — instant-recall named configurations with 3 built-in presets
• 10 drum patterns — rock, house, hip-hop, jazz, ambient, breakbeat, half-time, shuffle, latin-clave, bossa-nova
• 17 scales/modes — Major, Minor, Harmonic Minor, Melodic Minor, Pentatonic Major/Minor, Blues, Whole Tone, Diminished, Chromatic, Dorian, Phrygian, Lydian, Mixolydian, Ionian, Aeolian, Locrian
• Device profiles — persistent JSON profiles with CC mappings and velocity curves (~/.sqncr/devices/)
• Sonic Pi integration — OSC-based synth control, live loops, FX chains
• VCV Rack integration — patch generation from templates, headless launch
• Spectral analysis testing — frequency-domain validation of generated output
• Per-device telemetry — OpenTelemetry spans for every MIDI message and generation decision
• Polyrhythms — layered drum patterns with per-voice velocity and probability

You: "What MIDI devices do I have?"
→ list_devices
  Found 1 MIDI output device(s):
    [0] loopMIDI Port

You: "Open it and set up a Sonic Pi pad synth"
→ open_device(deviceName: "loopMIDI")
  Opened MIDI device: loopMIDI Port
→ setup_instrument(name: "Pad", type: "SonicPi", role: "Pad")
  ✅ Instrument 'Pad' set up — Ch 1, SonicPi, range 24-108

You: "Start something ambient in A minor, 90 BPM, moderate variety"
→ start_generation(tempo: 90, scale: "minor", rootNote: "A3", pattern: "ambient", variety: "moderate")
  Started generation: 90 BPM, A Minor (root A3), ambient pattern, octave 4, variety moderate

You: "Make it bluesier, smooth transition"
→ modify_generation(scale: "blues", smooth: true)
  Modified generation:
    Scale → A Blues (smooth)

You: "Save this as 'late-night-coding'"
→ save_session(name: "late-night-coding")
  Session 'late-night-coding' saved.

You: "Stop"
→ stop_generation
  Generation stopped.

src/
  SqncR.AppHost/           # Aspire orchestrator
  SqncR.Core/              # Generation engine, rhythm, instruments, persistence
  SqncR.Cli/               # CLI entry point
  SqncR.McpServer/         # MCP server + 30+ tool definitions
  SqncR.Midi/              # DryWetMidi MIDI I/O
  SqncR.ServiceDefaults/   # Shared OTel + resilience
  SqncR.SonicPi/           # Sonic Pi OSC integration
  SqncR.Testing/           # Spectral analysis, test helpers
  SqncR.Theory/            # Scales, modes, note parsing
  SqncR.VcvRack/           # VCV Rack patch generation + launcher

tests/
  SqncR.Core.Tests/
  SqncR.Integration.Tests/
  SqncR.Midi.Tests/
  SqncR.SonicPi.Tests/
  SqncR.Testing.Tests/
  SqncR.Theory.Tests/
  SqncR.VcvRack.Tests/

• MCP Integration Guide — full tool reference, parameters, and examples
• Blog: Building SqncR — From Zero to Generative Engine
• Blog: Software Synths — Sonic Pi & VCV Rack
• Blog: Stream-Ready Stability, Variety & Persistence
• Blog: Know Your Gear — Instruments & Multi-Channel

586 tests across 7 test projects.

• Unit tests — engine, theory, patterns, instruments, persistence
• Integration tests — end-to-end MCP tool flows
• Spectral analysis — frequency-domain validation of generated audio
• Canary tests — early-warning failure detection
• Failure recovery — engine resilience under intermittent MIDI failures

dotnet test SqncR.slnx

Contributions welcome! The repo uses:

• Branch strategy: main is the default branch
• .NET conventions: nullable enabled, implicit usings, TreatWarningsAsErrors (src/ only)
• Test coverage: new features should include tests

TBD

Maintainer: Brady Gaster (@bradygaster)

Built with: Music theory, MIDI magic, and conversational AI ✨🎹🎵