On 6 Nov 2007 at 14:36, Daryl Shawn wrote: > Perhaps most people are familiar with this, but this blows my mind...a > "Shepard tone", created of a particular combination of sine waves, I didn't know what it was called, but the clip you link to is amazing - thanks for sharing it. There's a similar effect (in reverse) at the end of Floyd's "echoes", where things rise and keep rising.