Katy Perry, Ed Sheeran, The Chainsmokers, Shawn Mendes, Thomas Rhett, Noah Cyrus and Big Sean join the previously announced Bruno Mars as performers at the 2017 iHeartRadio Music Awards. The fourth annual iHeartRadio Music Awards, hosted by Ryan Seacrest, will air live on TBS, TNT and TruTV on Sunday, March 5th.