it is pretty cool....but i dont get how it works

http://www.break.com/index/audio-halloween-illussion.html

Well, after lots of lost sleep and searching, the answer to this puzzle found me! I was driving home today while listening to NPR (National Public Radio). They were doing a bit on a composer who was using a "musical illusion" on which to base his new piece. Then they played something very similar to what you posted.

It's called a Shepherd's Scale. Instead of explaining how it works, check out this site. They do a much better job of it!

http://www.exploratorium.edu/exhibits/highest_note/ex.about.fr.html

For another example of a Shepard Glissando, check out the wikipedia article. At the very bottom, there is a link to it. Very interesting!
http://en.wikipedia.org/wiki/Shepard_tone

If you're interested, here is the link to the NPR article about the composer, Stephin Merritt. I believe they have a recording of the composition he created from the Shepherd's Scale.

http://www.npr.org/templates/story/story.php?storyId=15859351

BTW, You definitely get extra credit points for teaching me something new! I appreciate it!

YESS!!!...haha, but yeah i thought it was really cool. So yeah i will defenitly check that stuff out! But thanks for researching it!. It defenitly stumped me!

If you have it, give a listen to Pink Floyd's "Echoes" from their "Meddle" album. The last 40 seconds or so uses this device as well. Pretty neat!