# PlayByKey Music Theory

> PlayByKey Music Theory — com-playbykey-theory-mcp. Use this tool when you need to analyze or generate musical elements such as chords, scales, and progressions. It solves problems related to music composition, transposition, and MIDI file manipulation, providing a comprehensive interface for music theory tasks. With inputs including musical notes and outputs including chord progressions and MIDI files, it's ideal for AI agents working on music-related projects.

Canonical page: https://skillsregistry.net/skills/com-playbykey-theory-mcp  
JSON: https://api.skillsregistry.net/v1/skills/com-playbykey-theory-mcp

## Description

Chords, scales, progressions, transposition, and MIDI tools for music theory AI agents.

## Trust

- **Trust score (0–1):** 0.96
- **Verification tier:** verified
- **Last scanned:** 2026-09-19

## Facts

- **Version:** 1.6.0
- **Skill type:** atomic
- **Execution layer:** mcp-remote
- **Runtime environment:** api
- **Category:** media
- **Updated:** 2026-09-19

## Source

- **Source listing:** [MCP Registry](https://registry.modelcontextprotocol.io/v0/servers/com.playbykey%2Ftheory-mcp)
- **Repository:** <https://github.com/DigitalBrewLLC/playbykey-dev-tools>

## Use it

Resolve this record through the SkillsRegistry MCP server (no auth, read-only):

```
claude mcp add --transport http --scope user skillsregistry https://api.skillsregistry.net/mcp
```

```json
{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/call",
  "params": {
    "name": "get_skill",
    "arguments": {
      "slug": "com-playbykey-theory-mcp"
    }
  }
}
```

REST: `GET https://api.skillsregistry.net/v1/skills/com-playbykey-theory-mcp` · pull for local use: `GET https://api.skillsregistry.net/v1/skills/com-playbykey-theory-mcp/pull`

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SkillsRegistry indexes agent skills from public registries and GitHub. Skills we have analysed are scanned with Circle-IR and scored on six dimensions; each listing states its scan coverage. More: https://skillsregistry.net/llms.txt