Avril and Katy Rock as 'Idol' Judges
The cast of characters taking the open judge's musical chair on "American Idol" continues to grow. EW.com reports pop punktress Avril Lavigne and sexy singer Katy Perry will serve as guest judges on "Idol."
Sources tell EW.com that Lavigne and Perry will each spend one day as a judge when "Idol" films the callback auditions in Los Angeles.
Perry was rumored to have subbed at an "Idol" audition a few weeks back, but the "Waking Up in Vegas" songstress was never scheduled.