Abba tribute band Bjorn Again were the first band to appear at on the festival site at Worthy Farm, Pilton, Somerset - usually a 600-acre dairy farm. Up to 100,000 fans are expected, but ticket sales are said to be slightly down on last year.

The BBC's Jane O'Brien: "Sunshine is feeding the spirit of Glastonbury"

Crowds have been descending on the site at Worthy Farm, Pilton, Somerset since the gates opened on Sunday.

Friday's headliners include REM, Blondie, and the Beautiful South on the main stage, while Fatboy Slim and the Chemical Brothers play the dance tent.

Across the weekend, musical icons appearing include soul legend Al Green, former Clash frontman Joe Strummer, skiffle star Lonnie Donegan and punk poet Patti Smith. However, veteran rock star Ian Dury was forced to pull out on Thursday due to ill health.

The BBC's Jane O'Brien: A tented city the size of Bath

Other attractions include circus and theatre fields, fire-eaters and trapeze artists - and the chance to sing karaoke with comedian Keith Allen and former Clash frontman Joe Strummer. The duo are raising money for tree-planting programmes.

The site - which has become, in effect, a temporary city - also includes food from all corners of the world, markets, therapists, and tattooists.

But there are concessions to the late 1990s - cashpoints are on site, and a deal has been struck with a mobile phone operator to provide coverage for festivalgoers to phone home.

The previous two festivals - in 1997 and 1998 - were all but washed out after torrential rain, leading to this year's depressed ticket sales.

Arrests and crimes up

Campers wake up to glorious weather

But the fine weather is set to continue during the first part of the weekend, although rain is a real possibility on Saturday night and during Sunday.

But mindful of a barrage of criticism following last year's festival, festival organiser Michael Eavis - who has announced the festival will continue for a further five years - has spent the last six months working on new drainage channels to siphon off excess water.

Preparations were marred by an early crime wave, with 222 incidents reported to police, 50 more than the same time last year. The figures include 163 thefts of property from cars and tents. The Avon and Somerset force confirmed 89 arrests had been made by Friday morning, including 29 for theft and 26 for drugs offences.

Superintendent John Buckley, commander at the festival site said the increase in the number of arrests was partly a due to a policy of cracking down on "crime hotspots".

He said: "We will contunue to take a positive line to deal with the small minority intent on causing trouble and a number have already been ejected from the site."

Festival spokesman Crispin Aubrey advised people to take care and remain vigilant.

He said: "The trouble is people relax on the site and forget to look after their valuables.

"We do our best, but if we increased the police presence people would complain. We do have our own set of stewards as well, but they do not have powers of arrest."

There is live coverage of Glastonbury all weekend on BBC Radio 1, BBC Two, and on the digital TV channel BBC Choice. For more details, click here.