Irish rockers U2 face first-night nerves and the prospect of small protests as they prepare to make their Glastonbury debut on Friday at one of the world's biggest music festivals.
Tens of thousands of fans have descended on the site, a dairy farm in picturesque southwest England, braving fields of cloying mud caused by recent rain to catch a glimpse of their favorite acts on dozens of stages.
The main focus on Friday will be U2's set at the Pyramid stage, built at the bottom of a grassy slope where more than 100,000 people can stand, dance, cheer or jeer.
The band is in the middle of a record-breaking world tour, but has little experience of playing festivals where listeners have not only come to see them.
Drummer Larry Mullen, Jr. has admitted that the group would be out of its comfort zone.
"It's about a band being able to get up and play the music and there aren't bells and whistles necessarily," he said in a recent interview. "That's a challenge for us and we've got something to prove."
U2 had been due to perform in 2010, but had to pull out when lead singer Bono injured his back.
Tax Protest Planned
The band may also be aware of a campaign by a small pressure group called Art Uncut which wants to highlight U2's decision several years ago to move some operations from Ireland to the Netherlands for tax purposes.
Critics say Bono, a leading anti-poverty campaigner, should be prepared to pay full taxes in his homeland, particularly at a time of major financial difficulty.
On online forums, others argue it is the band's right to pay taxes legally wherever they wish, and that Bono works harder than most rock stars to highlight important global issues like poverty and disease.
"I think he can be a bit 'holier than thou' and then you see what is going on in Ireland," said Mel Meek, a 47-year-old at her second Glastonbury festival.
"He is so closely associated with Ireland and his country is in the crap. Then again, you don't believe everything you read in the press and he may be doing things we aren't reading about," she added.
Meek, like most of the crowd that will peak at around 175,000 people, wore rubber rainboots to cope with the mud.
Bales of hay were dropped over the worst-affected areas to making walking easier, and organizers politely asked people not to use water to rinse their boots.
"It's a real waste of our water supplies (and it's unlikely they'll stay clean)," a member of staff Tweeted on the festival's Web site.
Before U2's evening set, blues guitar legend B.B. King and contrarian Manchester singer Morrissey will take to the Pyramid stage.
The other headline acts are Coldplay on Saturday and Beyonce with the closing show on Sunday, following in the footsteps of her husband Jay-Z who won over the Glastonbury doubters with a rousing set in 2008.
Visitors have a bewildering choice of entertainment, with hundreds of bands performing across the 900-acre site.
Pop pundits have singled out Tinie Tempah, Plan B, Paul Simon, Primal Scream, Mumford & Sons, The Chemical Brothers, White Lies, Queens of the Stone Age, Cee Lo Green and Ke$ha as ones to watch.
Turned into a giant camping site most years, Britain's most famous music festival is now in its fifth decade.
The event has grown from a humble gathering of 1,500 people on Michael Eavis's Worthy Farm in 1970, each paying one pound ($1.60) and receiving free milk, to a giant celebration of music costing 195 pounds for a basic ticket.