Kenny Chesney, Rascal Flatts and Carrie Underwood are among the first artists revealed for the first-ever I Heart Radio Music Festival in Las Vegas on Sept. 23-24. More artists from a variety of genres will be added all summer. The event will also feature the Black Eyed Peas, Kelly Clarkson, Coldplay and Lady Gaga, among many others. Hosted by Ryan Seacrest, the festival will be held at the MGM Grand Garden Arena. Presale tickets are available at the festival's Facebook page. Tickets to the public will be available on Saturday (July 16). The event will stream live online and via mobile devices at IHeartRadio.com. Underwood will appear on Sept. 23, while Chesney, Clarkson and Rascal Flatts will perform on Sept. 24.