I've only gotten to try the music pack addons so far and GODDAMN THEY'RE GOOD! Thank you so much for those alone, they enhance the game experience by 10000%. When I accidently stumbled around the thread and saw that Vol 2 of music madness was out, I felt happiness unlike any other, since the first volume was amazing already.
If you make more volumes, I'd like to suggest
using this mod as a base for it, allowing the player to have a hotkey to switch to a random next track, randomizing music tracks per level, and having a much easier naming structure for the files (SONG001, SONG002) that can be automated by Advanced Renamer or similar programs.