Guest Stars John Legend as Himself Lady Gaga as Herself Chris Stapleton as Himself Sam Smith as Themselves Demi Lovato as Themselves Anna Kendrick as Herself Ariana Grande as Herself James Corden as Himself Gwen Stefani as Herself Carrie Underwood as Herself Bruno Mars as Himself Lionel Richie as Himself Kendrick Lamar as Himself Diplo as Himself Stevie Wonder as Himself Little Big Town as Themselves Selena Gomez as Herself Kaley Cuoco as Herself Seth MacFarlane as Himself Stephen Colbert as Himself Taylor Swift as Herself The Weeknd as Himself Ryan Seacrest as Himself Don Cheadle as Himself Gary Sinise as Himself Ice Cube as Himself Ellie Goulding as Herself Adele as Herself Justin Bieber as Himself Meghan Trainor as Herself Ed Sheeran as Himself Tyrese Gibson as Himself Pentatonix as Themselves O'Shea Jackson, Jr. as Himself Nile Rodgers as Himself Tori Kelly as Herself Joseph Simmons as Himself (Rev Run) Skrillex as Himself Cam as Herself Andra Day as Herself Luke Bryan as Himself James Bay as Himself Phillip Riggs as Himself Von Miller as Himself Anquan Boldin as Himself Irving Azoff as Himself Miguel as Himself Alabama Shakes as Themselves Sam Hunt as Himself