DioGuardi, whose work includes Kelly Clarkson's "Walk Away," Christina Aguilera's "Ain't No Other Man" and "We Rock," from the recent Disney Channel musical "Camp Rock," will serve as the fourth judge on the panel, alongside Simon Cowell, Randy Jackson and Paula Abdul.

DioGuardi will make her debut tomorrow as part of taping the eighth season audition rounds in New York. - more on this story

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