Demi Lovato [1] is one of our favorite performers, and not for nothing. The singer (who rocked the red carpet [2]) elevated the iHeartRadio Music Awards to a whole new level on Sunday night, performing a stripped-down version of her hit "Stone Cold." [3] Country superstar Brad Paisley skipped out on the ACM Awards to be on guitar duty for her. "Demi Lovato just sang her ass off," remarked Justin Timberlake [4], taking the stage after her. Watch it now; you won't regret it!