TOD:
I think the same solution would apply with a straight play or a musical.
It's no secret that Rex Harrison was disliked by most people who worked with him. So, in my play, SEXY REXY, I made him the butt of the jokes. He was such an outrageous a**hole that you sympathize with the other characters (e.g. Lilli Palmer, Kay Kendall, Rachel Roberts, Carole Landis), all of whom are "ghosts," and laugh AT Harrison.
I had a similar situation with my one-person play, JOLSON, but people go to an Al Jolson play to hear the songs. They "forgive" Jolson's being an a**hole when he sings.