The "music lock" [f5] opcode/function is broken on PC. It's being ignored (in blin67_3, for example). The PC version loses the lock on map change, when it should carry.
It gets reset to 0 (unlocked) at 63C060 on field change - when it should not. The function in question is 613FD9.
I am unsure if nopping this will solve the issue, but it's definitely worth a shot. This may also fix a lot of other issues in the game. The turks' theme not playing and so on.
If anyone wants to test that with me - change memory 63C060 to 90 90 90 90 90 90 90
It does appear to fix the issue. You can monitor the lock / unlock bit at CBF9C0
This should also fix the issue with Turks' Theme not playing, Cid's theme ending - and a ton more. I need to check though.
There are two other 00 resets near this address - and I wonder if those are doing something they shouldn't.