Geoff -- The Bullfrogs get this too! (The fact that you can play DB on other instruments is irrelevant -- the kind of dimwit who asks for it expects a banjo). I usually ask the requester to point out the banjo he'd like it played on. Funnily enough our drummer has recently taken up the banjo -- two musical stereotypes for the price of one! Maybe when he's good enough.... Incidentally Duelling Tubas was by Martin Mull and it's hilarious, as is his 2001 Polka.

BJ