Avril Lavigne to be guest judge on 'Idol'

LOS ANGELES, Sept. 3 (UPI) -- Canadian singer-songwriter Avril Lavigne has signed up to serve as a guest judge on TV's "American Idol" this season.

Paula Abdul's departure from the show after she and "Idol" producers failed to agree on a new contract has left the fourth panelist's chair empty.

TVGuide.com said Lavigne will appear alongside permanent judges Simon Cowell, Randy Jackson and Kara DioGuardi at the Season 9 contestant auditions in Los Angeles this week.

Katy Perry, whose appearance was previously announced but not scheduled, is also to help out this week, TVGuide.com said.

Other celebrity guest judges to appear on the show next season include Victoria Beckham, Mary J. Blige, Joe Jonas, Neil Patrick Harris and Kristin Chenoweth.