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Aerosmith frontman Steven Tyler and singer/ actress Jennifer Lopez were named the newest judges on "American Idol" Wednesday, ending weeks of rampant speculation as to who would join the panel on the hit Fox reality show.

The announcement was made in a live webcast at 1 p.m. on the show’s website. Host Ryan Seacrest introduced the panel, while a giant screen featured montages of Tyler and Lopez's work.

As the show moves into its 10th season, only one judge from the original lineup, Randy Jackson, remained.  Simon Cowell announced his departure earlier this year to move on to his new show “The X Factor.” Judges Kara DiGuardi  and Ellen DeGeneres also announced their departures in recent months.

By filling just two of the vacancies, "American Idol" is back to the three-judge panel that's been a mainstay for most of the show's run.

Whether Lopez and Tyler can recapture the offbeat chemistry that Cowell shared with Paula Abdul, who left last year in a contract dispute, remains to be seen.

Tyler said he wanted to join the show because "it's being a part of something much bigger than yourself. ... I want to bring some rock to this rollercoaster and show if you've got the heart, the talent, the feeling to do this you could be the next American Idol."

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"I'm so excited," Lopez said. "I'm looking for the next Michael Jackson."

Lopez and Tyler could help "American Idol" reinvent itself for the new season, when it will try to stem a ratings slide and bring in younger viewers. The show's audience has been gradually aging, and advertisers prefer to pitch to young adults.

But Fox and the show's producers didn't match the new judges to the target audience when it comes to age: Lopez is 41 and Tyler is 62. Jackson is in the middle at age 54.

Lopez's films include "Selena," "The Wedding Planner" and most recently "The Back-Up Plan." She has appeared as a mentor on "American Idol."

She was part of the "Fly Girl" house dancers on the comedy show "In Living Color," in 1990, before becoming a backup dancer for Janet Jackson.

"On the 6," Lopez's first album, came out in 1999 and launched a career in pop, Latin, hip-hop and R&B. "Love?" is the latest CD from the Grammy winner, who has twins with husband Marc Anthony.

Tyler brings a colorful and tempestuous history with him. He's fought with his band mates, been in rehab for prescription drug abuse and took a fall off a stage in 2009 that forced cancellation of Aerosmith's summer tour.

"American Idol" was the nation's favorite program last season, the seventh time it's held that position. But it showed rare vulnerability, beaten in the weekly ratings several times by ABC's "Dancing With the Stars."

A total of 24.2 million viewers watched the ninth season's final duel between Lee DeWyze and Crystal Bowersox, compared to the nearly 29 million viewers who saw Kris Allen claim victory over Adam Lambert last year.

The Associated Press contributed to this report.