A new judge for 'Idol'

American Idol has seen its share of contestant scandals, but when it comes to the basics of the show itself, shake-ups have been rare. That’s about to change. Last week, Fox announced that a fourth judge, producer-songwriter Kara DioGuardi, will trade barbs with Simon Cowell, Randy Jackson, and Paula Abdul next season. ”Change is good,” says Cowell. ”If you eat dinner with three people for seven years, you’ll get quite bored. A fourth person brings new opinions. It’s going to be interesting.”

But who is DioGuardi? She may not be a household name (yet), but you’ve heard her hits — she’s co-penned everything from Gwen Stefani’s ”Rich Girl” to Christina Aguilera’s ”Ain’t No Other Man.” She contributed to Kelly Clarkson’s second album and worked with current Idol champ David Cook. That résumé, says Charlie Feldman, a VP at publishing giant BMI, makes her a natural fit: ”Kara is a gifted songwriter, a successful producer, and an incredible singer. She’s very opinionated and strong. She and Simon are gonna be like two lions in the den.” And in case the foursome needs to break a tie, DioGuardi brags that ”I can get really loud.” Which leaves just one question: Where the heck will she sit?

— with additional reporting by Kate Ward

JUDGMENT DAY

Let’s hope Kara DioGuardi’s welcome is warmer than the ones these TV newcomers received.

1. Dawn (Michelle Trachtenberg)

Buffy the Vampire Slayer

2. Olivia (Raven-Symoné)

The Cosby Show

3. Cousin Oliver (Robbie Rist)

The Brady Bunch

4. Sam (Danny Cooksey)

Diff’rent Strokes