com.playbykey/theory-mcp
PlayByKey Music Theory
Chords, scales, progressions, transposition, and MIDI tools for music theory AI agents.
alive probed 2026-10-15
32tools
7.8ktokens in Claude Opus 5.5
8.1ktokens in Claude Code
3.9 %of a 200k context window
4.5ko200k_base estimate
133 msto initialize
3 msto list tools
- Run it
- npx -y @playbykey/theory-mcp@1.6.0 (stdio, probed in a container with the network off)
- Host
- npmjs.com
- Reports itself as
- theory-mcp 1.0.0
- Capabilities
- tools
- Instructions
- none
- Claude count
- Claude Opus 5.5, measured 2026-10-15. Counted again when the tool definitions change. Method.
- Repository
- https://github.com/DigitalBrewLLC/playbykey-dev-tools
- Registry
- active, updated 2026-07-28 · registry entry
- Reachable
- 1 of the last 1 probe
Most expensive tools
| Tool | Tokens (o200k) | Share of this server |
|---|---|---|
| transpose | 227 | 5 % |
| get_scale_degree | 217 | 5 % |
| is_note_in_scale | 206 | 5 % |
| get_chord_inversion | 200 | 4 % |
| get_sharps | 172 | 4 % |
Badge and feed
[](https://mcpcost.ulehla.dev/s/com.playbykey/theory-mcp)
An entry for every probe that changed the result, the tool count or the token cost: Atom feed. Add it to a feed reader or a Slack RSS app to hear when the server stops answering or its tool set grows.