Lady Gaga, Coldplay, the Black Eyed Peas and more are set to grace the stage of the 2011 iHeartRadio Music Festival. The two-day event will take place on Sept. 23 and 24 at the MGM Grand in Las Vegas, Nev.

The festival will help ring in "the new iHeartRadio," which will be available this fall. The lineup currently includes today's biggest artists in pop, rock, R&B, country and hip-hop, including: Steven Tyler, Alicia Keys, Kenny Chesney, Jennifer Lopez, Carrie Underwood, Nicki Minaj, Jane's Addiciton, John Mayer, David Guetta, Rascal Flatts, Bruno Mars, Kelly Clarkson, Usher, Sting and Sublime With Rome.

More performers and guests will be announced throughout the summer, but the lineup is already stacked with stars. Fans can access an exclusive ticket pre-sale now on Facebook.com/iheartradio, and the general sale will begin on Saturday, July 16 at 1PM ET via Ticketmaster.

Listeners on a budget can win one of hundreds of free trips to the festival through iHeartRadio by listening to its stations and liking its Facebook page. Those who can't make it there in person will also have the chance to stream the event live on iHeartRadio.com and via its mobile phone and tablet app.

Watch Ryan Seacrest Talk About the 2011 iHeartRadio Music Festival