Ariana Grande wore cat ears, Taylor Swift was pretty in pink at iHeartRadio Festival

Ariana Grande, Iggy Azalea, Taylor Swift, Ed Sheeran, Coldplay, 5 Seconds of Summer, One Direction, Usher, Weezer, Paramore and other huge pop acts too the stage at the MGM Grand in Las Vegas for the iHeartRadio festival. Check out photos of many of the acts who rocked the weekend.