I suppose the most obvious thing to say would be stuff along the lines of "dueling bajos," but please don't suggest that.
Sorry if this sounds stupid but this is one instrument that I am totally ignorant of.
I was camping a couple of months ago and one of the guys camping with us started playing his banjo: good instrumental stuff that was actually suitable for the campfire setting. I could go for something more complex than that, but I'm not sure if I want anything with vocals.

