The world's biggest stars including the likes of Ed Sheeran, Alessia Cara, Katy Perry and Tove Lo guest host the iHeartRadio Countdown with JK (Jack Laurence) every week, counting down the weeks 20 hottest thumbed up songs as voted by YOU on iHeartRadio!

Tune in to the iHeartRadio Countdown Sundays 4-6pm on KIIS1065 SydneyKIIS101.1 Melbourne and 97.3FM Brisbane, or 24/7 on iHeartRadio.