Modest is a Lua library that offers a harmony toolkit, including Chord, Note, and Interval objects. It supports various chord types, from basic triads to extended and altered chords. The library provides flexible string parsing, Unicode and ASCII accidental representations, and immutability in object handling. Noteworthy is the reliance on LPeg and Fennel, which requires additional installation steps for manual setup. Modest emphasizes simplicity and correctness, offering methods for chord identification, transposition, note retrieval, and more. The library is suitable for Lua 5.x versions, LuaJIT, and provides extensive documentation. A surprising feature is Modest’s naming after Modest Petrovich Mussorgsky.
https://github.com/esbudylin/modest