Well my recollections of "banjo" humour go back to reading "Three Men in a Boat" many many years ago. This is a gentle Edwardian humorous book about three friends (not forgetting the dog) who set of on a camping/boating holiday on the Thames suffering many vicissitudes - not the least of which is one of their number deciding that it is the "ideal" opportunity to learn to play banjo!

p.s. Some of my best friends are banjo players - honest