I read somewhere (I think Charles Shaar Murray's book about Hendrix but I don't remember) about when Janis Joplin performed in a soul-context (she was opening for a soul-act or playing in a "black" club or something) and showed up showing no restraint and generally losing herself in the music in her typical way and people booed her and she couldn't understand why because she felt she was a soul-artist. I think a pretty high degree of professionalism and self-control was expected of the soul artists by the audience who I guess defined them which BTW is why the "wild" and "free" hippies were quoted as saying stuff like "spade music (note:not my words) is square and republican" in the late 60's...