Here's a tune called Whalen's Breakdown from the book Canadian Fiddle Styles by April Verch and Brian Wicklund. It's in the key of C.
First I recorded myself playing the chords on banjo uke. Then I played back back the recording of the chords and added the melody over it on tenor banjo. So what you hear is a recording of a recording of the chords. Not the proper way to do this at all but I was just fooling around with combining tenor banjo and banjo uke. It sounds old-timey and almost syncs up around the 3rd time through the tune. Kinda sounds halfway decent for having never really tried something like this before.
I plan on learning some more about how to multi-track soon. There's audacity, and some multi-track apps for the iPhone. I also need a USB microphone for my computer, I think.