The Shepard Effect

So Professor Olsen was talking about a musical scale that gives the illusion of forever increasing melody. I did a Google search and found a similar scale called the Shepard Effect. It's actually very clever and mind boggling at the same time.

I found an interesting website that offers a helpful Java representation of how the effect works. The visualization shows how the different notes interchange volume to the create the auditory illusion.

Link: http://www.netalive.org/tinkering/shepard-effect/