Beyonce was persuaded to headline Glastonbury by Coldplay's Chris Martin.
The Bootylicious singer - who is close friends with Chris and his wife Gwyneth Paltrow - was reportedly reluctant to play at the festival after the strong reaction to her husband Jay-Z headlining the event in the past, but Chris helped reassure her.
Glastonbury organiser Emily Eavis told the Radio Times: "Chris is a bit wary of people knowing he's been so involved.
"I don't know why because it's actually cool. Chris is loyal as they come; he'll do anything for Glastonbury. He's really an unlikely frontman. Most people are a bit more all-consumed with their own thing."
When Jay-Z was announced to be performing at the festival in 2008 some Glastonbury traditionalists, including Oasis guitarist Noel Gallagher, complained about a hip-hop act headlining the festival.
But seeing the great crowd reaction Jay-Z received made Beyonce keen to perform on the Pyramid stage herself.
Emily said: "Luckily we spoke to Beyonce before she planned her tour this year, so she managed to put Glastonbury in her schedule, then build a European tour around it.
"And her split from her manager dad was all happening at the same time. That was partly why we've had to have lots of personal contacts involved."