# @playbykey/theory

Project, Worldwide.

> Music theory TypeScript engine and MCP server
>
> — in its own words, from theory-engine.docs.playbykey.com

- Website: https://theory-engine.docs.playbykey.com/
- Listed since: 2026
- launched: 2026-07-11
- launch post: https://news.ycombinator.com/item?id=48867938
- hn score: 2
- domain created: 2025-07-25
- Last verified: 2026-07-11


## Sources

- Hacker News, "Show HN" — https://news.ycombinator.com/item?id=48867938, read 2026-07-11

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startup.is · https://startup.is/projects/playbykey-theory · open data: /api/v1, /llms.txt