You should be! I'd love to see how it works if you wouldn't mind sharing. I'm also a musician so this game really intrigues me.
Sure! The source code is here. We actually use the audio instance instead of a timer to drive gameplay, which keeps gameplay in sync with the music at all times. The exact BPM of the song is specified in a config file, and then we have a helper run condition called on_beat (which is actually on every eighth-beat, for extra granularity).
Oh wow yeah! Looking at music.rs, I see how it's set up and that's super fascinating. I'd love to talk more about this if you'd like to add me on Discord (on my itch page) if y'all want to implement a feature in this game. About 3-4 years ago, I created a mathematical proof of what I called the "nth" swing (yes, not just triplet swing) and I'd love to talk with your group all about it because adding swung beats would be an insane feature to have in a game like this.