Gary I know that feeling.
One time I was doing a job and right in the middle of a song while I was singing this woman stands right in from of me and starts waving her hands. She got me so damm mad that I actually stop playing. The dance floor was full. Over the microphone I said nice and loud, "lady what the hell do you want? I can't sing and talk to you at the same time. Can't you see that I'm working and have a full dance floor. What's so important that you couldn't wait until I finished this song?"
Well she turn around and meekly walk back to her table. And guess what...the audience knew how rude she was and gave me a round of applause.
Then I continued with the song and finished the job.
I've never done anything like that before but this was a frustrating situation to say the least and the audience understood.

P.S. The job was a success!!

Peter