Macy`s iHeartRadio Rising Star Christina Grimmie performs during the 2015 iHeartRadio Music Festival at the MGM Grand Garden Arena in Las Vegas, Nevada September 18, 2015. Photo: ReutersMacy`s iHeartRadio Rising Star Christina Grimmie performs with dancers during the 2015 iHeartRadio Music Festival at the MGM Grand Garden Arena in Las Vegas, Nevada September 18, 2015. Photo: ReutersBritish singer Sam Smith (C) performs with Disclosure, a British electronic music duo of brothers Howard and Guy Lawrence, during the 2015 iHeartRadio Music Festival at the MGM Grand Garden Arena in Las Vegas, Nevada September 18, 2015. Photo: ReutersConfetti falls on the audience during the 2015 iHeartRadio Music Festival at the MGM Grand Garden Arena in Las Vegas, Nevada September 18, 2015.Photo: ReutersFall Out Boy vocalist and guitarist Patrick Stump performs during the second night of the 2015 iHeartRadio Music Festival at the MGM Grand Garden Arena in Las Vegas, Nevada September 19, 2015. Photo: ReutersBusta Rhymes (R) performs with Puff Daddy during the second night of the 2015 iHeartRadio Music Festival at the MGM Grand Garden Arena in Las Vegas, Nevada September 19, 2015. Photo: ReutersPuff Daddy (L) performs with Tori Kelly during the second night of the 2015 iHeartRadio Music Festival at the MGM Grand Garden Arena in Las Vegas, Nevada September 19, 2015. Photo: ReutersHozier performs during the second night of the 2015 iHeartRadio Music Festival at the MGM Grand Garden Arena in Las Vegas, Nevada September 19, 2015. Photo: ReutersBlake Shelton performs during the second night of the 2015 iHeartRadio Music Festival at the MGM Grand Garden Arena in Las Vegas, Nevada September 19, 2015. Photo: ReutersHailee Steinfeld performs during the 2015 iHeartRadio Daytime Village in Las Vegas, Nevada September 19, 2015. Photo: ReutersFans react to a performance during the 2015 iHeartRadio Daytime Village in Las Vegas, Nevada September 19, 2015. Photo: ReutersNick Jonas performs during the 2015 iHeartRadio Daytime Village in Las Vegas, Nevada September 19, 2015. Photo: ReutersJames Bay performs during the 2015 iHeartRadio Daytime Village in Las Vegas, Nevada September 19, 2015. Photo: Reuters
