The iHeart Radio Music Festival returns to Las Vegas again for 2012.  The concert will be September 21-22 and will feature the biggest names in music today.  The line-up is set to be released on July 9th.

Last year's iHeart Radio Festival featured Coldplay, Lady Gaga, Jennifer Lopez, Nicki Minaj, Bruno Mars, Kelly Clarkson, David Guetta, Carrie Underwood, and The Black Eyed Peas.