Rick, do you mean specific to music, or in general society?

At any rate, here is a bit I found:

"According to Brewster's Dictionary of Phrase and Fable, sin-eaters were the poor persons hired at funerals in Medieval Times, to eat beside the corpse and so take upon themselves the sins of the diseased, that the soul might be delivered from Purgatory. This tradition of sin-eating has been recorded in England, Ireland, Wales, Eastern Europe and even in India. Though there may be cultural variation, a unifying theme of this job is that, the sin-eaters are poor persons, and because they take others' sins on to themselves, they are generally viewed as unclean and stand outside the general community."