While I can't think of anywhere else that has those themes off the top of my head, I would assume that music unlocks are triggered (mainly) by whatever teleports you/activates an event that leads to a change in music, so it might be worth trying to get to the places you dont have music for by entering them from all possible warps, like for _seagull, going from the sunken city building jump, leave tapir-san's building, enter via the piano form the dark theater etc.
On the other hand, I've heard some tracks are a bit buggy and dont unlock when they're supposed to, but i know i have all 5 versions of _Seagull, so that can't be bugged