I've actually been having a lot of fun at the restaurant gigs I've been playing lately, and looking forward to this Saturday night when I get to play one with a sax/flute/guitar/banjo/harmonica player I've worked with before ... and he plays them all WELL!!! ...and we're BOTH singing ... however, I don't know how much I would enjoy a FULL 3-4 hour instrumental only gig ...
Frank (Mockie), I don't know what your repertoire consists of, but depending on the venue, when you take a break you might want to put on a CD of music quite the opposite of what you are playing ... for example, I have this CD which I often play when (if ) I take a break
http://www.amazon.com/The-Beatles-Guitar-Jack-Jezzro/dp/B000040OUE



Have fun ...