iHeartRadio 2013: Katy Perry, Elton John roll out the hits

LAS VEGAS -- To get a sense of how much music -- and how much corporate appeasement -- was crammed into the first night of this weekend's iHeartRadio Music Festival, consider this: Robin Thicke, whose "Blurred Lines" recently topped the Hot 100 for 12 weeks in a row, played one song.