The stars came out in full force in Las Vegas over the weekend as the MGM Grand Hotel and Casino saw the likes of Jay-Z, Nicki Minaj, Usher, Alicia Keys, Bruno Mars, the Black Eyed Peas, Lady Gaga and Jennifer Lopez take to the stage at the iHeartRadio music festival.

Billed the biggest live music event in radio history, the two day event also saw Justin Timberlake, Rob Kardashian and Nicole Scherzinger in attendance.

Grammy award winner Alicia Keys played a new ballad called, 'A Place Of My Own' for the first time while Jay-Z filled a 40-minute set with hits like, '99 Problems,' 'Dirt Off Your Shoulder,' 'Big Pimpin',' and 'Run This Town,' with Keys joining him for ‘Empire State Of Mind.”

Jennifer Lopez revisited the earlier hits of her back catalogue with a rendition of ‘Jenny from The Block’ and got the crowd moving with her most recent show stopper ‘On The Floor.’

Nicki Minaj tore through a selection of hits from her LP Pink Friday with a series of trademark facial expressions and her usual high-energy delivery, and DJ David Guetta debuted a song with R&B singer Usher.

Have a look at the best bits in our gallery below….

iHeartRadio Music Festival 2011 in Las Vegas...