Awesome game
As much as I like this game, I agree with some of the other users that the excessive amount of options makes the game difficult for people who don't know a lot about music. Its easier for someone like me who plays guitar and knows scales to write some good songs in this game than it is for most of the people playing this. I'd suggest giving more tips like showing some major/minor scales. It could be helpful for people who want to do more than to stick to playing in one key.
Playing in shows is challenging, but to me that's a good thing. The only problem is the lag, but that's not too big of a deal once you learn how to play songs/covers. I really like the customization options and how you included tabs.
Overall, this game is awesome and a big improvement over the first.