Right On, Don!!!
I don't know which is worse: A) having a guest singer that makes the crowd groan, or B) having one that is better than me.

Hey! It happens.
Tonight I am filling in for a guy at private club where the format for the evening is "open mic" and encouragement of group singing. Management knows this is a departure from what I normally do...but they fully explained the program to me and I appreciate knowing in advance what it is all about. So, no one will be turned away..and what happens, happens. They even video tape the singers and play it back during breaks to jeers and cheers at the bar.
Yeah, its kinda Karaoke-ish...but at least they hired a live player to do the job.
Eddie