I love your work on this - a good heatmap library is super helpful, and this is a very clever way to demonstrate it. And that QR code demo you posted earlier is pretty sweet, too...good weekend, huh?
Robert Taub is a phenomenal pianist. The app is quite cool and slickly done as well. I can see the complains, esp. here, about the essence of any new (or not new) IP, but Taub got my $5 bucks back in the day to hear him play, and he got my $7.99 today.