A fourth judge will join the "American Idol" panel, host Ryan Seacrest announced on his radio show today.
The addition? Kara DioGuardi, a singer, songwriter, producer and artist. Her songs have been recorded by artists like Christina Aguilera, Carrie Underwood and Celine Dion, according to DioGuardi's official Web site (www.karadioguardi.com).
DioGuardi will join judges Paula Abdul, Randy Jackson and Simon Cowell for the eighth season of "Idol," slated to premiere in January.



