Ever checked out the Hieronymous Bosch painting "The Garden of Earthy Delights"? Not one for spawning sweet dreams. We're talking mangled people, half-animal monstrosities, all manner of disgusting detritus realized on a sprawling, impressive scale.
In one of the many vignettes it holds, a poor soul suffers being a human music stand--notation is written out across his butt. Hard to believe no one has done it in, oh, the last half-millenium plus, but an enterprising blogger finally made a recording of the notation. About which I can only say, "Go, Internet."
Then another cheeky sort put the music to a choral score, which is surprisingly nice, and quite medieval-sounding. Well, except for all the lyrics about butts and hell.
I'm reminded of the old Irish tune "The Town I Loved So Well": "There was music there in the Derry air..."
Here's the original (just one part of the massive painting), in which we apparently see Hell's house band. Musical bum at bottom left: