But couldn't this be possible, whether it's for the prop or music?
the point is that if the tape only goes in if you call setMusic on the brick, you can just as easily key other events to happen at the same time - there's no need to make a tape in/out input event.
ex: onActivate > self > setmusic
onActivate > self > do something else
or onRelay > namedbrick > setmusic
onRelay > namedbrick > do something else