I got this idea during one the montages of the show. I'm curious on what band the two would like, or just what each of them like? Like it seems they both enjoy rock, but just as well enjoy rap and pop songs.
From what I've seen of the show, Rigby seems to have a bad taste in music. like with that episode with party Pete, and the living in summer time episode. I'm not sure about Mordecai, though if i had to guess he's more of a rock guy or more accurately indie rock.
I honestly cant think of any bands off the top of my head, but if you guys have any of a band they would be into, don't be afraid to throw a name out there.