I'm currently working on a Python-based demonstration of some music theory concept for an article in the Paged Out! magazine. Very early stages but it might provide some inspiration regarding how to describe music theory concepts using code: https://github.com/tiniuclx/harmonylib

I've also made a "music theory interpreter" in Rust that goes a bit further. The source files for music theory & the chord database might prove especially interesting. https://github.com/tiniuclx/harmony-explorer

Finally, Ian Ring's website is a very fascinating place to learn about scales in particular: https://ianring.com/musictheory/scales/