LOS ANGELES (Reuters) - Pop star and actress Jennifer Lopez and Aerosmith rocker Steven Tyler are joining TV singing contest "American Idol" as judges in a major overhaul aimed at keeping the show No. 1 with viewers as it enters its 10th year.
Producers on Wednesday announced the signing of Lopez, 41, the singer and star of movies such as "The Wedding Planner", and Tyler, 61, at a glitzy event in Los Angeles that ended months of speculation over who would join the judging panel.
Record producer Randy Jackson remains the only original judge since the program debuted on Fox television in 2001, and Ryan Seacrest will remain as host.
"American Idol" producers announced other big changes to get away from what they called the "karaoke" feel of the show when it returns to U.S. television in January 2011 after a four year ratings decline.
Universal Music executive Jimmy Iovine will act as an in-house mentor and will be featured behind the scenes working weekly with aspiring pop stars as they compete to become the 2011 "American Idol."
Major record producers like Timbaland also will work with the contestants, but celebrity guest mentors will not be used and contestants must dance more. The moves are a bid to find genuine stars like first champion Kelly Clarkson who went on to a Grammy-winning career.
"We are 10 years-old and we are being given the opportunity to recreate the magic," returning executive producer Nigel Lythgoe said at a news conference announcing the changes. "We have got to go back to creating an 'American Idol'"
Lopez and Tyler replace British judge Simon Cowell, talk show host Ellen DeGeneres and songwriter Kara DioGuardi as the judging panel returns to its original three-person format.
Tyler said on Wednesday he wanted to "bring some rock to this rollercoaster".
"I want to give everybody a little love before I decide who goes home heartbroken. If you don't like what I say, don't get mad, get better," the colorful Aerosmith showman added.
Lopez, star of movies like "The Wedding Planner", said she had long been a fan of the show and that the opportunity to be a judge "felt like the right thing at the right time for me."
"American Idol" has generated huge advertising revenues for Fox over the years and boosted record sales and digital downloads for early winners like Clarkson and Carrie Underwood.
But despite being the most-watched TV show in the United States for eight years, "American Idol" has lost about six million viewers since 2006, and recent winners have largely failed to translate their success into chart-topping careers.
Lythgoe said that contestants would no longer be made to sing different genres each week, like country, disco or rock, but would be encouraged to perfect their own original style.
"It has been alleged we are a bit of a karaoke show," he said. "We have a whole new set of rules. We are not just going to copy tracks. And they are no longer just going to be standing there, like shoe-gazers. We will want them to move. I want the focus to go back on the kids and their talent."
Brian Friedman, one of the executive producers of TV show "America's Got Talent", said "Idol" needed changes to keep it fresh.
"The last thing you want is your studio audience and viewers at home to be able to predict the show. You have got to keep everyone on their toes," Friedman told Reuters.
"American Idol" is produced by 19 Entertainment, a unit of CKX Inc and FremantleMedia, a unit of Bertelsmann AG-controlled broadcaster RTL Group. Fox is a unit of News Corp.
Editing by Bob Tourtellotte