The same week that the "American Idol" finale registered record low ratings-20.7 million viewers, according to preliminary figures from Nielsen, a 29% drop compared with last season's finale-ABC makes its entree into singing competitions with the nine-week series "Duets," adding yet another twist to the "Idol" model.

The catch with "Duets" is that four professional artists-Kelly Clarkson, John Legend, Jennifer Nettles and Robin Thicke-not only coach two contestants each, but also perform duets with them. The judges then assess each performance, with the two lowest-ranked singers facing off with a final tune sung a cappella. The contestant scoring best gets saved, while the other must leave the show.

The show, which debuted May 24, taped the first five two-hour episodes earlier in the month. Four weeks of live shows begin June 28, and the ultimate winner will receive a contract with Hollywood Records, which, like ABC, is owned by Disney.

Clarkson says ABC executives first approached her at an awards show and convinced her that the new series would celebrate creative pairings of different artists. "The best parts of awards shows are collaborations," she says, "and I love that they have based a whole show on that collaborative process."

Nettles, Thicke and Legend - the lattermost replacing Lionel Richie, who dropped out of the show in late April, citing what a rep called "personal scheduling conflicts" - agreed with Clarkson that the main draw was the performance element. The winning mentor/singer will perform 18 songs by the show's end, an important factor for Clarkson, who is still working singles from her "Stronger" album. Legend, on the other hand, was readying a new album and only had to work around studio time to make himself available.

"You get to sing on every show twice," Thicke says, explaining why the series appealed to him. "I only had one song that played on pop radio - all of my stuff gets played on black radio - and TV offers a great chance to be heard. It was completely selfish at first. Then I met these [contestants], and now my biggest concern is giving them their best chance to succeed."

The eight contestants auditioned through various means including YouTube submissions and an open call of about 100 singers so Legend could replace Richie's former duo. Nettles asked the performing arts school where she studied for a recommendation, and wound up singing with the music director of her grandmother's church.

"I didn't want to have to teach someone about pitch," the Sugarland singer says. "They had to feel comfortable onstage [and have] the ability to interpret."

Like other TV contests, audiences can expect many popular songs and, like "The Voice," they'll hear a certain level of professionalism from the get-go (e.g., no William Hungs). Rehearsals for the first five tapings were tightly scheduled - just a half-hour with a solo piano, a half-hour with the band and a half-hour of staging.

Legend says popular songs were deliberately chosen to give the audience "something they can relate to. You don't want to force them to get to know a new song and a new talent at the same time."