Cook's ad for the game by Activision is pretty funny:
Finally, someone that the kids might actually know. The Jonas Brothers performed to cheers.
David Archuleta sings with One Republic on their song "Apologize."
Last year's winner, Jordin Sparks is back with "One Step at a Time."
Gladys Knight auditions Ben Stiller, Jack Black and Robert Downey Jr.
Carrie Underwood, one of the most successful Idol winners, is back with "Last Name."
And not to be outdone, Archuleta also cut a "Guitar Hero" ad. Archuleta is a boxers guy. Judging from Cook's ad, he either wears briefs or goes commando.