Rock Band is a game that was created by the makers of Guitar Hero III, Harmonix. It is a game sort of like DDR, where you have to press buttons in the order as they appear on the screen to create a song; however, in this game instead of stepping on a dance pad, you have a makeshift guitar, drums, or a microphone to "press buttons" with. With the guitar you have to press the keypads and strum the trigger at the base of the controller, just like a guitar! With the Drums, you hit drum pads and a kick pedal, sorta like real drums; and with the mic you sing into it and tap it like a tamborine, uh....I guess its a little like real singing lol.
I've been playing this game for a while and it is crazy fun. No matter what instrument you play, as long as you have friends over, you are guarenteed to have a good time. However, if you play alone, you might get bored after a long while because you have noone else there to play with (who ever heard of a one man rock band? Get some friends over STAT). The only downside to this game is the INASNE amount of money it costs to buy everything in a bundle pack (169.99!!!! O_O) I mean seriously holy crap thats a lot of money. Its about half of what it costs to buy the damn system to play it on! LOL.
All in all, the game is worth it; although, you should probably wait a bit until buy it, just to make sure you are financially secure to be buying this videogame. And try to stay away from open windows, because if your meighbors don't know what rock band or Guitar hero is, they'll think you've gone insane XD.