All I can think of is Little Nicky and the dude with boobs on his head. I'm not the first to mention it, but I never read comments first anyway. Head bra is a fun touch.
A Cerberus with a dragon tail? Okay. But their right on the music.
With 3 heads, each one have it's own moment in Time, listens to music, they would be receiving 3 times the amount of input. Thus... putting them to sleep.
@SomeGuy1 It's probably not supposed to just completely make her not able to hear anything, it probably just does it enough to make it harder to hear the music but it also makes it harder to hear someone you're talking to