At this 'summer stampede' event in the former Olympic Park, they'll be joined by a well-picked supporting cast. Vampire Weekend are essentially their New York counterparts, what with their knack for blending anthemic indie balladeering with elements of folk music – from Africa in VW's case, from the California dustbowl in the Mumsons' – not to mention their elite education. The bill also includes Brit-winning surf troubadour Ben Howard, Edward Sharpe And The Magnetic Zeroes – whose road-worn Americana isn't a million miles from the headliners' – and Haim, the breezy West Coast trio who have been compared to Fleetwood Mac but also sound a lot like Wilson Phillips. Opening the whole event are Bear's Den, three bearded Londoners who play, er, banjo-heavy folk-pop. In fact, if you don't like banjos, you'd do best to stay away entirely.