SunVox is a neat program for writing music.
There also exists a JavaScript SunVox library that's easy to use and exposes a whole bunch of useful functions for manipulating the music dynamically from JS.
It would be really neat to tinker further with SunVox in some web-based GameDev and procedural art things that muck with the music more than just a simple .wav player.
I started into that in Swinth 2020, but have yet to do anything interesting in terms of interactions between the graphics & sound.
I'd kind of like to come up with some generative songs that get their parameters tweaked by events in a game - or vice versa, music that tweaks visual parameters.