Kelly Clarkson thrills fans at Troubadour show

Kelly Clarkson was in fine form as she performed a not-so-secret show at the Troubadour in West Hollywood on Tuesday night. The one-time American Idol star was previewing her new album "Stronger" before a crowd that included adoring members of her fan club and the press.

Backed by a seven-piece band, including two backup singers, the former "American Idol" star ripped through a 50-minute set mixing in old and new songs, including "Miss Independent," "Walk Away" and the title track of the new album, which will be released October 24, "What Doesn't Kill You (Makes You Stronger)."

The crowd, who all seemed to have their cells and cameras out taking pictures and videos, sang along with "Breakaway" as she held out the mic to them. Clarkson brought out a cellist to accompany her on a cover of "Carnival Ride" a tune she heard fellow "Idol" star Carrie Underwood perform recently.

Though she records on RCA, its parent company is Sony, who had placed a number of their new interactive wireless television sets in the club's bar in order to let fans vote for Clarkson's encore song. The winner turned out to be "Sober," but the singer chose to do it midway through the set and though she said she was rusty gave a soulful rendition of the tune.

Instead, she treated the crowd to a rocking "If I Can't Have You." After the lights went out, audience members spotted country music and TV star Reba McEntire in the balcony and started taking snaps of her as the theme from "True Blood,"

"(I Want to Do) Bad Things) to You," played in the background.