Vi Hart's "Peace for Triple Piano"

While going through the Musical Assumptions "archives," I was happy to find myself re-aquainted with Vi Hart, a brilliant mathematician/musician who tickles my love of things math-related even though I have no way of understanding any of it once she is finished explaining things with her magical set of markers.

You can watch a video about the making of this video here.

And then, if you want more (who wouldn't?) and you have half an hour to be enlightened/entertained, you might enjoy her take on twelve-tone music.