I'd like to ask you if you've ever played Guitar Hero or GH2?

If you have not then for crying out loud DO IT! And please tell me how you did.. I play on Normal difficulty at the moment, and I've tried the hard one a coupple of times but HELL that is hard

I allways loose my way with the buttons and the speed is insane, so can anyone give me a hint on how to ace GH on Hard or Expert for that matter?