Extra-terrestrials bent on dominating Earth, I mean, should it ever turn out they exist.
In the meantime, between gnashing of teeth and contemplating the alien menace (as likely as not to emerge in the form of an asteroid hurtling towards Earth) consider enjoying some websites about music
Aurgasm : not exactly sure how it works, some music comes out.
GrooveShark : if you know the song, they play the song.
CherryPeel : don't know the song? other people vote on them.