British folk rockers Mumford & Sons fear they are taking the "risk" of their careers by headlining Britain's iconic Glastonbury festival this year (13) because they are convinced they aren't established enough to be performing at the top of the bill. The I Will Wait hitmakers will close the 2013 event by playing the main stage on 30 June (13), following in the wake of fellow headliners the Rolling Stones and Arctic Monkeys. But the bandmates are terrified to be playing such a prominent spot, because they only have two records of material to draw from. Frontman Marcus Mumford tells Time Out magazine, "It's a really huge deal to headline Glastonbury; we're a young band with only two records behind us. This summer is probably the biggest risk we've ever taken." Bandmate Winston Marshall adds, "I've seen The Stones play for three hours and the crowd knew every song. It's what you want in a headline slot at a festival. I'm scared because it feels like a gamble. We don't know if we've earned it yet or not."