18 of the hottest hits by Maroon 5, Nicki Minaj, Rita Ora, Carly Rae Jepsen, Demi Lovato, Karmin, Rihanna, Justin Bieber, Usher, Drake, One Direction, Reece Mastin, Ellie Goulding, Annabel Fay, Conor Maynard, Sammy Adams, Hot Chelle Rae, and Jamie McDell.