[Jewbacca]

hey i'm not sure if this is the right forum but i was wondering if anyone knew about a game that is like "sing it" or "rockband" singing game where it grades you on pitch and stuff for mac. preferably i would like one where you can make your own track on your own song. if this is for windows that would be ok too but i was just playing rock band with a bunch of friends and thught it would be cool to have a freeware game like that. the equivalent of frets of fire is to guitar hero