Offering a variety of artists in popular music, stations in the iHeartRadio network gave away hundreds of trips to the "biggest live music event in radio history" held at the MGM Grand Garden Arena on the Las Vegas Strip from September 23–24, 2011 The second annual iHeartRadio Festival will take place September 21–22, 2012 at the MGM Grand Garden Arena in Las Vegas. List of performers were announced on July 9, 2012. Photos Below: Rihanna Performing Lil wayne Gwen Stefani and Pink. On September 18, Shakira announced that she was pregnant and had to drop out of the festival. [18] Guest presenters include Britney Spears , Ryan Lochte , Demi Lovato , Miley Cyrus , LL Cool J , Ryan Seacrest , and Kathy Griffin . [19] In 2012, iHeartRadio held a contest for new and upcoming artists to enter and win the chance to perform at the iHeartRadio Music Festival, to be held in Las Vegas in September of that year. Artists Megan and Liz,