Bill D - An exception, IMHO, is the blues. I read somewhere and agreed with it wholeheartedly that when a blues singer was performing (a solo, acoustic blues like in the 1930's) he was singing and playing to himself, really. Others were welcome to listen in of course, but it was primarily a means of self consolation.

I don't want to generalize too much, there were a lot of blues done to entertain others and provide music for dancing, also to solicit donations etc.