Okay here's the information on it.
Grooveshark is a revolutionary music community that rewards users for sharing their music. Grooveshark was founded by three University of Florida students hell-bent on changing the music industry, and the world, forever. Grooveshark's goal is to compensate everyone in the value chain from users to rights' holders.
It has a nice interface and a good concept, but it costs money to download the music. Really all I use it for is listening to songs (they're free to listen to and are in good quality), but you can also promote and upload your own music and you can make some money off of that.
Just make a post with your e-mail and you'll get it.