Maybe you could ask your local music store if they can do a rental plus lessons deal? 1. Didn't like the uke 2. Didn't like the banjo music you played him I hate to sound pessimistic, but those two things make me think he might move on from the banjo just like the uke. That could be good though, trying out a bunch of things until he finds one to stick with... as long as you're not stuck with a bunch of left over cheap banjos and ukuleles!