Custom music becomes garbled after some time

Hello. I'm starting to experiment with inserting music into Mario 64 and so far I've been having decent luck, until after a few moments of playing one of the songs it suddenly becomes glitchy and static-y, for lack of a better term, probably due to the high volume levels in the music (and since they seem to go away when Mario falls asleep).

If anyone can help out with fixing this problem of mine, it'd be greatly appreciated