Turn up the volume and prepare to be hypnotized! Click on the black arrow to switch between "ascending" and "descending" mode.
Warning: if you're like me, you'll find this amusing. But if not, there's a chance you'll find it really annoying or even headache-inducing. In that case, just turn it off and go listen to your favorite music! :-)
I recently visited the San Francisco exploratorium for the zillionth time, and I stumbled upon the "infinite keyboard" exhibit which has always fascinated me. Here's my attempt to recreate that effect: a perpetually-ascending (or -descending) sequence of notes!
The image is of a Penrose Staircase. When I was 12 I spent a long time figuring out exactly how the perspective trick works, and then drew one myself. It's fun and you should give it a try.