Jan here (from the PWA team). Sometimes I think back fondly on the times we ran across someone who was convinced they weren't musical, and yet the game had them playing in minutes.
A couple of years ago, we met a man who was 60% deaf. His mother had been telling him since he was extremely young that he would never play a musical instrument. He accepted that -- well, that is until he met us.
We invited him to a demo and had a camera rolling as he read musical notes, and played a melody by Beethoven in about 10 minutes. The whole room was cheering as he looked square into the camera and said, "My mother was wrong!"
Do you know anyone who is carrying around the mistaken idea that music is out of their reach?