iHeartRadio Festival 2014
Ariana Grande performs onstage during the 2014 iHeartRadio Music Festival at the MGM Grand Garden Arena on September 19, 2014, in Las Vegas.
Taylor Swift
Taylor Swift performs onstage during the 2014 iHeartRadio Music Festival at the MGM Grand Garden Arena on Sept. 19, 2014, in Las Vegas.
One Direction
Musicians Harry Styles, Liam Payne, Niall Horan, Zayn Malik, and Louis Tomlinson of One Direction perform onstage during the 2014 iHeartRadio Music Festival at the MGM Grand Garden Arena on Sept. 20, 2014, in Las Vegas.
Darren Criss
Actor Darren Criss speaks onstage during the 2014 iHeartRadio Music Festival Village on Sept. 20, 2014, in Las Vegas.
Alicia Keys
Alicia Keys performs onstage during the 2014 iHeartRadio Music Festival at the MGM Grand Garden Arena on Sept. 19, 2014, in Las Vegas.
Calvin Harris
DJ Calvin Harris performs onstage during the 2014 iHeartRadio Music Festival at the MGM Grand Garden Arena on Sept. 20, 2014, in Las Vegas.
Iggy Azalea
Rapper Iggy Azalea performs onstage during the 2014 iHeartRadio Music Festival at the MGM Grand Garden Arena on Sept. 20, 2014, in Las Vegas.
Jennifer Lawrence
Actress Jennifer Lawrence attends the 2014 iHeartRadio Music Festival at the MGM Grand Garden Arena on Sept. 19, 2014, in Las Vegas.
Colton Haynes
Colton Haynes attends the 2014 iHeartRadio Music Festival at the MGM Grand Garden Arena on Sept. 19, 2014, in Las Vegas.
Jermaine Dupri
Jermaine Dupri attends the 2014 iHeartRadio Music Festival at the MGM Grand Garden Arena on Sept. 19, 2014, in Las Vegas.
Pete Wentz
Pete Wentz of Fall Out Boy attends the 2014 iHeartRadio Music Festival at the MGM Grand Garden Arena on Sept. 19, 2014, in Las Vegas.
Cecily Strong
Cecily Strong attends the 2014 iHeartRadio Music Festival at the MGM Grand Garden Arena on Sept. 19, 2014, in Las Vegas.
Jason Derulo
Jason Derulo attends the 2014 iHeartRadio Music Festival at the MGM Grand Garden Arena on Sept. 19, 2014, in Las Vegas.
Nick Jonas
Nick Jonas attends the 2014 iHeartRadio Music Festival at the MGM Grand Garden Arena on Sept. 19, 2014 in Las Vegas.
Karina Smirnoff
Professional dancer Karina Smirnoff and Randy Couture attend the 2014 iHeartRadio Music Festival at the MGM Grand Garden Arena on Sept. 19, 2014, in Las Vegas.
Ariana Grande
Ariana Grande attends the 2014 iHeartRadio Music Festival at the MGM Grand Garden Arena on Sept. 19, 2014, in Las Vegas.
Casper Smart
Choreographer Casper Smart attends the 2014 iHeartRadio Music Festival at the MGM Grand Garden Arena on Sept. 19, 2014, in Las Vegas.
will.i.am
Recording artist will.i.am attends the 2014 iHeartRadio Music Festival at the MGM Grand Garden Arena on Sept. 19, 2014, in Las Vegas.
Kacey Musgraves
Singer Kacey Musgraves performs onstage during the 2014 iHeartRadio Music Festival Village on Sept. 20, 2014, in Las Vegas.
One Direction
From left, Recording artists Niall Horan, Harry Styles, Liam Payne, Zayne Malik, and Louis Tomlinson of music group One Direction attend the 2014 iHeartRadio Music Festival at the MGM Grand Garden Arena on Sept. 20, 2014, in Las Vegas.
Paramore
From left, musicians Taylor York, Hayley Williams and Jeremy Davis of Paramore pose in the press room during the 2014 iHeartRadio Music Festival at MGM Grand Garden Arena on Sept. 20, 2014, in Las Vegas.
Anna Faris & Chris Pratt
Actors Anna Faris and Chris Pratt pose in the press room during the 2014 iHeartRadio Music Festival at MGM Grand Garden Arena on Sept. 20, 2014, in Las Vegas.
Macklemore
Musician Christopher Mansfield of Fences and rapper Macklemore attend the 2014 iHeartRadio Music Festival at the MGM Grand Garden Arena on Sept. 20, 2014, in Las Vegas.
Nick Cannon
Nick Cannon attends the 2014 iHeartRadio Music Festival at the MGM Grand Garden Arena on Sept. 20, 2014, in Las Vegas.
Taryn Manning
Actress Taryn Manning attends the 2014 iHeartRadio Music Festival at the MGM Grand Garden Arena on Sept. 20, 2014, in Las Vegas.
Sophia Bush
Actress Sophia Bush attends the 2014 iHeartRadio Music Festival at the MGM Grand Garden Arena on Sept. 20, 2014, in Las Vegas.
Eric Church
Eric Church attends the 2014 iHeartRadio Music Festival at the MGM Grand Garden Arena on Sept. 20, 2014, in Las Vegas.
Hayley Williams
Hayley Williams of the music group Paramore performs onstage during the 2014 iHeartRadio Music Festival at the MGM Grand Garden Arena on Sept. 20, 2014, in Las Vegas.
50 Cent
Curtis "50 Cent" Jackson of the music group G-Unit and recording artist Fergie attend the 2014 iHeartRadio Music Festival at the MGM Grand Garden Arena on Sept. 20, 2014, in Las Vegas.
Macklemore & Ed Sheeran
Macklemore and Ed Sheeran attend the 2014 iHeartRadio Music Festival at the MGM Grand Garden Arena on Sept. 20, 2014, in Las Vegas.
Hilary Duff
Hilary Duff attends the 2014 iHeartRadio Music Festival at the MGM Grand Garden Arena on Sept. 20, 2014, in Las Vegas.
Chris Harrison
Television personality Chris Harrison arrives at the after party for the 2014 iHeartRadio Music Festival at Haze Nightclub at the Aria Resort & Casino at CityCenter on September 20, 2014, in Las Vegas.
Darren Criss
Actor Darren Criss arrives at the after party for the 2014 iHeartRadio Music Festival at Haze Nightclub at the Aria Resort & Casino at CityCenter on Sept. 20, 2014, in Las Vegas.