iHeartRadio Fest 2013 LIVE: Katy Perry, Robin Thicke, Adam Lambert / Queen & More Performances

Friday performance highlights of the 2013 iHeartRadio Music Festival include Katy Perry, Robin Thicke, Adam Lambert, Queen, Elton John, Muse, Tiesto, J.Cole, TLC, Keith Urban, fun., Ylvis, and more (Sept. 20, 2013)