See Kelly Clarkson's Soaring Cover of Garth Brooks' 'We Shall Be Free'

Vocalist also performed with Steve Wariner during Brooks' recent Nashville concert

Kelly Clarkson sang Garth Brooks' "We Shall Be Free" at Brooks' Nashville celebration.

"I'm just a mom, I haven't actually worked in a while," Kelly Clarkson joked Monday night as she took the stage at Nashville's Ascend Amphitheater during Garth Brooks' epic celebration in recognition of his seven diamond-certified LPs, signifying sales in excess of 10 million each. Although she's currently in mommy-mode, with a six-month old son, 2-year-old daughter and two older stepchildren at home, Clarkson reminded the crowd that she hasn't given up her singing career, belting out a gospel-infused take on Brooks' inclusive, socially conscious 1992 hit "We Shall Be Free." Clarkson had plenty of help from the nearly 7,000 concertgoers, but certainly didn't need it, even capping off the sizzling performance with vocal runs reminiscent of her title-winning American Idol season.

Clarkson also had a hand (and voice) in another of the night's impressive performances, which included guest appearances from Reba, Jason Aldean, Chris Young and Trisha Yearwood. After special guest Steve Wariner appeared to sing with Brooks on "Longneck Bottle," the 1997 chart-topper Wariner co-wrote and sang on, Clarkson lamented that Wariner hadn't performred what was obviously one of her favorite tunes, "The Weekend," a Number One hit for Wariner in 1987.

Whether spontaneously or by design, Brooks wielded his considerable clout to encourage the gifted guitarist-songwriter to return to the spotlight, where a jubilant Clarkson joined him on harmony and also let him serenade her on the romantic, jazz-fueled tune. At one point, Wariner, 61, rested his head on the singer's shoulder, interjecting, "I've known her since she was that big," indicating with his hand that she was a small child. "We're the same age, you're fine. Go with it," the 34-year-old Clarkson joked.

She also earned laughs by following Wariner's lyric, "If I can't have you tonight," when she quipped, "You can, Steve." Unable to contain herself, Clarkson then executed what was perhaps the least mommy-like move of the night, gleefully grinding behind Wariner as he attempted to finish the song. For a night under the stars, celebration and spontaneity were in abundant supply and Clarkson bubbled over with both.