Beyonce Knowles performs at the Glastonbury Festival at Worthy Farm, Pilton on June 26, 2011 in Glastonbury, England. The festival, which started in 1970 when several hundred hippies paid 1 GBP to watch Marc Bolan, has grown into Europe's largest music festival attracting more than 175,000 people over five days. (Photo by Dave Hogan/Getty Images)

Festival goers dance in a late night after hours venue London Underground in the Block 9 area at the Glastonbury Festival site at Worthy Farm, Pilton on June 27, 2011. This year's festival features headline acts U2, Coldplay and Beyonce. (Photo by Matt Cardy/Getty Images)