By LYNN ELBER
AP Television Writer

LOS ANGELES (AP) ó The flat notes, the sweet surprises, the pleas of the rejected are all intact as “American Idol” returns for its eighth season of first-class karaoke.

A new twist is the bikini-clad contestant who splits the judges straight down the gender line in the debut episode.

Fox previewed the show Monday night for TV critics who simply couldn’t wait 24 hours to see it air. The rest of America can judge for itself from 8-10 p.m. Tuesday.

The episode opens with auditions taped in Phoenix and features newcomer Kara DioGuardi, who joins Paula Abdul, Simon Cowell and Randy Jackson on the judging panel.

DioGuardi immediately distinguished herself by throwing down with the willowy woman in the very orange, very small bikini. DioGuardi, a songwriter-producer who also knows how to belt a tune, sang a few bars to show the contestant how it should have been done.

“Honestly, you don’t have the chops to sing that song, sweetie,” DioGuardi told her.

“But your demonstration wasn’t any better,” the woman snapped back.

Not diplomatic, Abdul cautioned, jumping into the fray.

But the male judges were definitely impressed.

“Beautiful,” Cowell pronounced after hearing just a few bars.

From Jackson: “I think you have a have a lot of potential. I’m going to say yes.”

That bikini is going to Hollywood and the next round of auditions.

Not so lucky was the extremely nervous man who was sweating as if he knew the executioner’s ax hovered.

“You look like you’re in pain or something,” Cowell told him.

The British music producer was his usual amusing, acidic self. Jackson appeared loose and eager for another season, chair-dancing to the rhythm of more than one bad singer.

Definitely no, Jackson told one contestant, then added gleefully, “Man, that was wild!”

A pink cowboy-hatted teenager pleaded for another shot.

“Please, I’m shaking in my boots here,” she pleaded, charmingly.

Boots, it turns out, are not as persuasive as a bathing suit.