OK, I might have encouraged that idea, since I've been annoying friends and family with polytonal versions for years. In fact, I just allotted myself exactly one chance to toss a quick sample recording together. We travel from C Major all the way up to C Major. I wasn't at all warmed up, so the L.H. got a little tired at times, and it's pretty unmusical - just like the kids play it. Here it is, although I'm sure I'll feel the need to fix it up at some point. It's also now installed at #8 on the MMmusic page, right between Poulenc and Scriabin. Piano blogging rides again!
Three quick points:
1) After playing it this way for years, the polytonal versions don't sound at all odd to me. I'm not saying I don't notice relative degrees of dissonance, but all the keys sound "right." If I start to lose my moral center as well, I'll let you know.
2) This would be a great exercise for piano class students, to get their fingers to "think" in various keys. Of course, they should also switch up the L.H., which I was too lazy to do. We're debuting a new piano class for non-majors this year; I'm not teaching it, but wouldn't it be cool to hear this up and down the halls day after day? (Meanwhile, my family members are shaking their heads thinking, "this is the day in Michael's blogging career we hoped would never come, but it was inevitable.")
3) If you think I haven't already considered the possibility of using Shepard Tones to create an endlessly rising version of this, you haven't been paying much attention. [UPDATE (later that day): Mission accomplished.]