Glad you've decided to continue working on this
MM music would be pretty good since you're limited by OOT, and I kind of like MM music so it would be nice. Maybe throw in some windwaker music if you happen to find any files for it.
I have a couple suggestions I want to make though. I think temple of time music doesn't really suit Undercity, maybe some Shadow Temple music would be better. For Stormwind, I think it would be cool if you had they Hyrule Town music for the whole town instead of temple of time music, aside from the cathedral of light. Also maybe change the music in Ironforge to Goron City music too. Don't think I'm hating on temple of time either
I could make a list with some changes I think would work for some existing zones but that would be taking over your project here which I am not trying to do. I love your MPQ here and hope it keeps getting better!