Okay . . . you were INVITED to accompany him on HIS gig. Up to the moment you are still a PROSPECT. Alright, you are pacing and leading the room, but that doesn't alter the fact that it's HIS gig. Yes, it's nice to have a regular stint close to home, but (and I think you know this already) just walk away from this one, keep on plugging management - it's only fair competition (they've seen and heard what you can do, and if this drummer guy is as duff as you paint him, he'll be gonzo pretty soon).