Coldplay and Lady Gaga set for iHeartRadio Music Festival

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Lady Gaga, Coldplay and The Black Eyed Peas have signed up to appear at the iHeartRadio Music Festival.

The two-day spectacle - billed as "the biggest live music event in radio history" - is set to take place at the MGM Grand hotel in Las Vegas on September 23 and 24, and will feature performances from some of the biggest pop stars in the world including Nicki Minaj, Alicia Keys, Bruno Mars, Jennifer Lopez and Sting.

Announcing the show in a video statement, host Ryan Seacrest said: "This is a once in a generation gathering of artists and fans from all over the country for a true, must-see music event. Listeners from all over America will travel to Las Vegas to celebrate the next generation of iHeart Radio, while seeing the greatest musicians in the world on one stage."

The Black Eyed Peas will break their recently announced hiatus to appear at the event, which also sees acts from other genres such as country stars Carrie Underwood, Kenny Chesney and Rascal Flatts and rockers such as Aerosmith frontman Steven Tyler, Jane's Addiction and John Mayer perform. Usher is also lined up for a guest appearance.

Further announcements of additional artists to join the bill will be made in coming weeks.