Lego Rock Band PS3 just playing background
My Lego rock band for PS3 seems to just play the background, characters playing and singing, but nothing to play to, no notes coming down...nothing, its like I am just watching a cartoon video of each song. It worked when I first purchased the game for a while, then the next time I played it, it just shows the background playing..nothing else. Tried Freeplay and story...nothing to play. HELP!