Building on Frederic Vavrille's Liveplasm site (a visual search engine he created 3 years ago), Mr. Vavrille has created a visually-entertaining web radio where listeners select music from a mood-energy matrix or from a genre selection box. Manuel Lima states that Mr. Vavrille combined sound from Pandora and Last.FM with Liveplasm to create a dynamic mind-map of related music. He calls it Musicovery
Some have reported that it doesn't work quite right - songs won't stop and the classification needs work. But I think it's a whole lot of fun! And, you have to admit it's a great looking piece of human-computer engineering.
"At sea once more we had to pass the Sirens, whose sweet singing lures sailors to their doom. I had stopped up the ears of my crew with wax, and I alone listened while lashed to the mast, powerless to steer toward shipwreck."
Stephen Travis Pope has released a significant upgrade to Siren and it is now available at the Siren site. Along with the upgrade are updates to the documentation and a fantastic video tutorial available in lo-fi (94 MB) and hi-fi (240 MB). If you're just curious, check out the video - Stephen explains the many capabilities of Siren in a clear and understanding way.
I sent Peter Kern a 1 second excerpt from Marble Madness for his 1-second music roundup (a challenge to create music that lasts a mere 1 second.) Check it out here.