My best practice is having each layout on it's own event sheet, plus "Include event sheet" for shared events. (Such as your character events all on one sheet, then have a level, and it's assigned sheet is "level sheet")
From this each layout can be fine tuned via it's own event sheet. So on the layout specific sheet, do this:
At start of layout
- Stop all (or "stop" and choose a tag to stop playing)
- Play song