Guest Stars Bebe Rexha as Herself Kelly Clarkson as Herself Alicia Keys as Herself Charlie Puth as Himself Chris Blue as Himself Bastille as Themselves Billy Ray Cyrus as Himself Demi Lovato as Themselves Vince Gill as Himself Jessie J as Herself Sia as Herself Drew Pinsky as Himself Norah Jones as Herself N.E.R.D. as Themselves Billy Idol as Himself Steve Stevens as Himself