Bark at the Moon.. enough to make me want to cry on medium. Haven't gotten through to it on hard yet I dont think.
You want to really screw with yourself? Try going back to Medium or Easy.. it's SO SLOW it screws you up. Heh. I have problems with the songs that are heavily dependent on lifts and hammers. For some reason I just can't get it to register with regularity. I haven't moved on to Expert yet. I've been trying to get through all the songs on Hard.. which has been a bit.. well.. hard.
That, and I just haven't had much time. School is kicking my a-hole right now.
Oh, and yes, I totally agree that having previous experience with guitar playing is a bonus once you get the hang of things. I can say that it wouldn't be impossible for a non-guitar player to do well (how many negatives was that again?).. and the way the game walks you slowly up in speed and complexity. It is, on the whole, a lot of fun to play. I wish it had more "meat" to the experience (as I said before).. but it's still a lot of fun.