# PlayByKey Music Theory

> PlayByKey Music Theory, an MCP server by playbykey.com, listed from the official MCP registry. Indexed, not reviewed: facts and our own checks, no score or ranking. Chords, scales, progressions, transposition, and MIDI tools for music theory AI agents.

- Canonical: https://www.anchorterminal.com/tools/playbykey-theory-mcp
- Markdown: https://www.anchorterminal.com/tools/playbykey-theory-mcp.md (~450 tokens)
- Slim: https://www.anchorterminal.com/tools/playbykey-theory-mcp.min.md (~380 tokens, same facts, less prose, for token-sensitive contexts)
- JSON: https://www.anchorterminal.com/tools/playbykey-theory-mcp.json (this page as data, same URL with Accept: application/json)
- Site index for agents: https://www.anchorterminal.com/llms.txt (full text: https://www.anchorterminal.com/llms-full.txt)
- API: https://www.anchorterminal.com/api/v1/index.json
- Updated: 2026-10-04

# PlayByKey Music Theory

> Indexed, not reviewed: facts from the official MCP registry and our own checks. No score, grade or rank, and not in the rankings until the panel reviews it. How the index works: https://www.anchorterminal.com/indexed/

- Kind: MCP server, by playbykey.com (https://playbykey.com)
- Category: Music generation (https://www.anchorterminal.com/categories/music-generation.md)
- Listed because: It's published in the registry under playbykey.com, a namespace the registry only gives to whoever proves they control that domain.
- What the official MCP registry says: Chords, scales, progressions, transposition, and MIDI tools for music theory AI agents.

## Facts

- MCP registry: `com.playbykey/theory-mcp` 1.6.0
- Package: npm `@playbykey/theory-mcp` (stdio)
- Source: https://github.com/DigitalBrewLLC/playbykey-dev-tools
- npm downloads a week: 112
- GitHub stars: 1
- Registry entry updated: 2026-07-28

- JSON: https://www.anchorterminal.com/api/v1/tools/playbykey-theory-mcp.json
- Being indexed says nothing about quality, and nobody can pay for it. Ask for a review: https://www.anchorterminal.com/builders/#claiming