Gar, not at all. This happens to me on occasion as well. It's not only restricted to OMB arranger keyboard gigs, but even when singing & playing 'acoustic piano' on piano bar gigs as well. Depending onthe situation as well as my mood, I'll either ignore them, or engage them in conversation right in the middle of the song, right over the PA system. I might respond with a saracasticly humorous reply in song maintaining the original melody, or perhaps direct the mic under the intruder's face, having his/her voice broadcast over the PA system, of which typically embarrasses them. The best way to deal with unintentionally rude patrons is to respond in kind with humor. If they're stoned drunk, that's another matter, and that's the job of house management to boot them out, and they do. This is the firm agreement I make with all house management before I sign on to a gig. This leaves me free to do what I'm PAID to do: Sing & play.

Scott