By Ian Youngs
Entertainment reporter, BBC News at the Glastonbury Festival
The Glastonbury Festival is hosting some of the biggest names in rock and pop - but few people know about the work that goes on backstage to make sure the show runs smoothly.
Chris Fitch watched as The Cribs' singer dived into the crowd
Chris Fitch strides over to a control panel in the wings and slides a button down like he owns the stage.
As production manager of the Other Stage - Glastonbury's second largest arena - he more-or-less does.
As he slides the button, the DJ fades out and the crowd assembled below lets out a cheer.
Yorkshire indie band The Cribs swagger on from the far side of the stage, lead singer Ryan Jarman raises his plastic pint glass to the audience and their set begins.
Mr Fitch wanders purposefully back behind the huge curtain at the back of the stage. He is responsible for getting every band and their equipment on and off on time - and, with 11 bands a day over three days, it is hard work.
The Other Stage is as big and complex as a main stage at other festivals, and is playing host to the likes of Bjork, Iggy Pop, The Chemical Brothers and the Arcade Fire this weekend.
But after 17 years working on the stage, Mr Fitch has made the process of getting bands in and out a tightly regimented operation.
Every band must unload, set up and test their equipment before going on stage, and then pack it back up and ship it back out again afterwards - but there are only 20-30 minutes between performances.
Equipment is rolled on and off stage on risers
So while one band is playing, the next act's equipment is set up backstage, ready to be rolled on.
Every band has "risers" - low platforms on wheels that allow gear, such as drum kits or keyboards, to be assembled behind the scenes and wheeled out as soon as the stage is vacated.
The Other Stage also has two parallel audio systems. When one is being used, the next band's equipment can be plugged into the second while they are waiting, which is then switched on when they begin.
As well as having the second band's gear ready and waiting, there is a third set of risers behind the stage, where the following group's kit is being prepared.
And a fourth set - for the band after that - may also be getting ready. Then there is a final set, belonging to the band who have just come off, being dismantled.
The process is a continual circuit - when one set of equipment comes off stage in one direction, another is immediately wheeled on at the other side.
The Other Stage's field can hold about 40,000 fans
"Viewed from above, we rotate clockwise all day," according to the production manager.
So while The Cribs are performing, the long, narrow space directly behind the stage is tightly packed with kit belonging to Modest Mouse, who are on next, and The Automatic, who are on after them, as well as Reverend and the Makers, who have just finished.
"When a band has finished their performance, it will be straight back in their van and gone as quickly as we can get rid of them," Mr Fitch says.
"In the nicest possible way, but we need the space for other people."
The activity, with people moving cases, instruments and cables from one place to another, can be frantic.
And behind the riser set-up area is another packed area for storing equipment belonging to the acts still to come.
Some bands only bring themselves, their instruments and minimal other equipment and personnel. The festival's own production crew do much of the moving.
But big acts, like tonight's headliner Bjork, can bring a huge amount of kit and an army of workers.
Bjork is headlining - and wants to put on a real show. She has bought two trucks of equipment and room has had to be found to stack it under tarpaulins at the side of the stage, with labels saying things like "Bjork - Unique Hazer II" and "UV Gun".
Back on stage, The Cribs have one roadie - or "back-line tech" as they should be known.
"Unfortunately, you can't use the word roadie without it being pejorative," Mr Fitch says. "It's a term of abuse."
The Cribs' back-line tech leans on a rack of guitars and occasionally scurries on stage to fix a tambourine, pick up Ryan Jarman's shoes as he goes barefoot or move his pint glass, which is in danger of being knocked over.
Big acts, however, usually have one tech for each member of the band.
Kit is assembled and dismantled backstage
Jarman finds the beer and downs it in one. He rips off his already-ripped shirt, jumps off the stage and launches himself over the safety barrier and into the crowd, before promptly being hauled back by two security men.
As soon as he is back on stage, and the band have finished their final flourish, Mr Fitch strolls over to their risers, pulls out the power and the activity immediately begins to move their equipment off.
Their risers roll by, their backdrop is pulled down and Modest Mouse's equipment is moved on almost straight away at the other side of the stage - and the process starts again.