'American Idol' Guest Judges Are An 'Eye-Opener,' Randy Jackson Says

'They actually know how to critique,' he says of Mary J. Blige, Katy Perry, Avril Lavigne and other celeb judges.

Back in August, long before Simon Cowell's departure was the big story surrounding the "American Idol" judges' panel, Paula Abdul announced her exit from the show. The move left producers scrambling to fill her seat for the soon-to-tape auditions, and they rounded up an impressive roster of guest judges for the job.

With season nine set to start Tuesday night (January 12), we'll get our first glimpse of the celeb judges in action, with Victoria Beckham kicking things off at the Boston tryouts. Randy Jackson was impressed with Posh Spice, even giving her a new moniker.

"I gave her the nickname 'Lady V,' " he laughed. "So hopefully she goes out into the world and uses that. ... People know of her fame from the Spice Girls — they probably know more of it as being Mrs. David Beckham — but [the guest judges] are all performers in their own right that have achieved high acclaim and massive success in the entertainment field."

Those judges also include Katy Perry, Avril Lavigne and Joe Jonas, all of whom brought something different to the table, Jackson said.

"If you sat down and you watched Katy or you watched Avril or any of these people we had as guest judges, you realize that their success is based on that they actually know what they're doing," he said. "They actually know how to critique, because, in order to make it to any of these levels where Katy or Avril, for instance, have made it, you gotta be able to critique yourself first so you're able to improve. I think it's just an eye-opener. People take for granted that, 'Yeah, well, they just had a hit song. Whatever. What do they know?' But they actually really know what they're doing. It wasn't an eye-opener for me, but I think for a lot of people watching, they're gonna realize, 'Wow, they really do know what they're doing.' "

One judge the auditioners really stepped up their game for was Mary J. Blige, Jackson recalled.

"Mary is a serious, stand-in-your-shoes performer," he said. "She is not a performer that is gonna use a lot of props to make you enjoy the show more; you're really gonna enjoy her voice. I was just driving in the car the other day, and her version of [U2's] 'One' with Bono came on the radio. You're not seeing different weird outfits or weird dance moves; it's not about that. She's this stand-in-the-shoes kind of singer. I think a lot of kids that came in know that, and they were like, 'Whoa, this is Mary J.! We gotta show and prove now.' It was a good thing for these kids to step up and rev up to."

Shania Twain, Kristin Chenoweth and Neil Patrick Harris will also appear as guest judges until the audition episodes wrap up February 3.

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