Just tested the two screens in Balamb, and music plays normally after a card game there. The sound of seagulls is still there while playing a game though (not sure if it's like that in the original PS1 version). As for Shumi Village, I don't have a save with messed up instruments, sorry.
There are new music issues with the Remaster by the way. For example, the full versions of Ride On and Movin' are being played at the overworld whenever you ride the Ragnarok and in space respectively. Furthermore, there are reports about the soundtrack randomly switching between PS1 music and MIDI... Too bad.