Guitar Hero III help

[PyroManiak]

There's a Guitar hero III tournament at my school this friday and I took up a challenge from a friend not knowing it was Guitar Hero III...I took the bet because I'm extremely good at Guitar Hero II and assumed it was that game we were going to play...so What's the difference beetween II and III and what changes will I have to adjust to if there are any?

Also advise me whether or not I should back out because we are also going to have DDR and It'd be hard to convince him to play that instead but I could do it.


((Mainly I'm just interested in any gameplay changes but information about new songs would be good although Im inevitably pretty much screwed in that I don't get to practice any of the new songs)))