Mark Clark, did any of those play-by-ear people you know start playing piano in adulthood? All the play-by-ear piano players I know started in childhood. Also, it's a LOT longer until you're actually playing tunes on the piano by the play-by-ear method. It asks a lot of you. In contrast an autoharp or lap/mountain dulcimer have you up and running, so to speak, in much shorter order.

Alex