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