Tonight, VH1 will premiere VH1 Unplugged: Kelly Clarkson, which features the chart-topping star breaking down tracks from her latest album – plus a cover of Carrie Underwood's "I Know You Won't" and perennial sing-a-long "Since U Been Gone." Clarkson's impressive voice was in fine form at the taping in New York City last month, shining over the bare-bones arrangements of the up-tempo pop tunes. Between songs, Clarkson was easy going and candid, telling the crowd her sky-high heels and body-hugging red dress were her "diva look" and, after messing up lyrics to "Mr. Know It All" on the first take, joking "the whole time I was like, 'stop!' and I didn't stop. It's like my relationships." When it came time for her to tackle Underwood's ballad, Clarkson defined her take on the "singer's song" as "a little more bluesy." Watch her belt it out above and judge for yourself.