Hey dude, long time no see. With this game, to get 5 stars, you pretty much have to abuse the rewind feature. Find a section that is quite easy (Usually around the start of the song), and go through it with Star Power if you can, then get a rewind and go through it again. Your score will sky rocket, and the stars will rack up because unlike GH, the average multiplier doesn't seem to factor into your final rating.
I may have to play RockIt again, to see where you could rack up your score, as I can't remember how the song even plays.
Hey man, do you have any tips for DJ Hero? I'm playing on Hard and only have three songs left to 5*, the two Rock It songs and Groundhog of course. I was literally just a couple notes away from 5*ing Groundhog so I know I can do that with practise, but the other song just rapes me with the spikes/directional scratches