Harmonix launched music games into a whole new arena with the release of Rock Band last year. No longer did music games have to be about just playing the drums or the guitar or singing. All three elements were merged together into a cohesive and thoroughly enjoyable package. But while Rock Band was a breath of fresh air, it did have some issues. With the release of Rock Band 2 less than a year after the original, Harmonix addresses many of the past concerns and adds an awesome new online mode, certain to keep gamers rockin' for another year.
Source : IGN