Regarding the "Music Theory library" aspect, note that the CLI tool demonstrates use of the underlying Ruby library which has documentation here: * https://git

Regarding the "Music Theory library" aspect, note that the CLI tool demonstrates use of the underlying Ruby library which has documentation here: * https://github.com/pedrozath/coltrane/wiki/Core-music-theory-library https://github.com/pedrozath/coltrane/wiki/Core-music-theory... Additionally, the author wrote a post about the motivation for creating the library but it's a little difficult to find via the (now broken) link in the README, so here is a direct link to the archived page on the Wayback Machine: * https://web.archive.org/web/20170714063625/https://medium.com/@pedrozath/so-i-wrote-a-library-to-help-me-compose-music-ddb4ae7c8227 https://web.archive.org/web/20170714063625/https://medium.co... If anyone is interested in a similar music theory library for Javascript[0] I've had some success with this: * Tonal / Tonal.js https://github.com/tonaljs/tonal https://github.com/tonaljs/tonal [0] Or, in a pinch, even with a Godot 4 web export as I did for my (very incomplete) "AI and Games" Game Jam entry: https://rancidbacon.itch.io/the-conductor https://rancidbacon.itch.io/the-conductor (For reasons far too convoluted to go into now.)