The best party on the planet

From Jay-Z to Neil Diamond and Amy Winehouse - this year's Glastonbury promises to be more eclectic than ever. Andy Gill looks forward to a vintage weekend

Traditionally, only farmers and sailors regard the weather forecast with any more than merely passing interest. But this week, a whole other, less rural constituency will be keenly following the meteorological mysteries of these islands, as they are divined by the weather-wizards with their charts featuring ancient mystic symbols of sun and rain and lightning-bolt. And all to see whether or not to pack both wellies and walking-boots. Decisions, decisions!

For this weekend sees the return of the annual pilgrimage to Glastonbury to experience the world's greatest aggregation of mummers and minstrels, jokers and jugglers, accompanied by thousands of fellow travellers, many bearing the heraldic device of their calling, the floppy-spiked felt hat of many colours. In the process, they will push their personal-hygiene envelopes to newly aromatic levels, misplace many of their possessions, and acquire a crust of fine Somerset mud that will still be ingrained in their jeans after a year's diligent laundering. Such are the trials and tribulations faced by the modern festival-goer. Butwhatever obstacles and pitfalls they face, the possibility of disappointment is simply not on the agenda: these brave souls are determined to gorge themselves on the experience, a now-traditional rite of passage involving cheap wine, stir-fry noodles, an illicit spliff or two and, with any luck, a bunk-up in the pup-tent with someone with coloured hair. Ah, Glastonbury! Thy mystic history is born anew!

Last year, the Glastonbury Festival was voted one of the best parties on the planet in a survey on the Rough Guide website - beating out such events as the Trinidad Carnival, New Orleans Mardi Gras, Munich Oktoberfest and the Burning Man Festival. And deservedly so: none of these other events so assiduously ups its ante each year, through pioneering programming initiatives that constantly seek to broaden the festival's cultural range - and other, more ecologically conscious innovations, like the biodegradable tent-pegs that are to be distributed to festival- goers, made of material derived from wheat and potatoes (the pegs, as well as the festival-goers) which breaks down naturally if left behind.

This year, one of the more controversial innovations is the headlining presence of rapper Jay-Z on Saturday night - a sore thumb in an otherwise thoroughgoing indie line-up, he's even been blamed for the event's failure to sell as many tickets as in previous years. Noel Gallagher, for one, reckons he's just "wrong" for the event, and even Dizzee Rascal, while delighted that Jay-Z is appearing, is uncertain whether he has the crossover appeal of Eminem or Kanye West.

It's easy to understand the misgivings: as anyone who has attended hip-hop events can attest, a rapper's impact tends to be in inverse proportion to the size of the venue. What can be gripping and incisive in the intimate surroundings of a small club becomes less impressive in an arena, and utterly ineffectual at stadium- size, where even a dynamic rhymer like Eminem struggles to glean entertainment value from the staple stage diet of hectoring whilst grabbing his crotch. And when it's somebody simply celebrating his wealth, his business acumen, his success with the ladies, his cars, his jewellery, and himself in general, as Jay-Z does, the affections of a mud-drenched crowd subsisting on baked potatoes and beer may be a little hard to win.

The other headline story in the run-up to this year's festival concerns the appearance - or otherwise - of Amy Winehouse, who's been in hospital since June 16 receiving treatment for emphysema. The most recent reports confirm she'll be there, though her "support" slot immediately prior to Jay-Z's surely undervalues her achievement as the most successful and magnetic performer of the last few years - and does the rapper few favours, either. Expect a sizeable exodus in the direction of the Other Stage following her set, for Massive Attack's headline appearance there. Canny punters, however, should make sure they stick around between The Raconteurs' set and Amy's to catch the performance by Manu Chao.

The temporal arc of the festival is fairly predictable by now. Friday's line-up tends to feature unchallenging, meat'n'spuds rockers to loosen the punters up a bit, and this year's is no exception, with sundry Fratellis, Editors and Subways supporting Kings of Leon. Elsewhere, thesmaller stages offer the most interesting prospects, with sets from Jimmy Cliff, The Ting Tings, Candi Staton, John Cale, Pete Doherty, Santogold, Alabama 3, Sinead O'Connor and Seasick Steve, the latter's headlining stint - a taster to his Pyramid Stage appearance the following day.

Besides the acts already mentioned, Saturday's bill includes sets by Duffy, Elbow, Hot Chip, British Sea Power and Gruff Rhys's latest project Neon Neon, along with the mouth-watering prospect of Gallic slackers The Teenagers, hot New Yorker combo Vampire Weekend and the enticingly-named Holy Fuck on the John Peel Stage. Perhaps dreaming of a Neil Diamond-style career revival, old hands Gilbert O'Sullivan and Andy Fairweather-Lowe both appear on the Acoustic Stage on Saturday; but the day's most intriguing listing is surely on the Park Stage, where Brazilian indie-dance group CSS, math-rockers Battles and American alt.rockers MGMT are supported by Music Through Unconventional Means with Shlomos Vocal Orchestra & Special Guests: if that isn't code for something to do with Damon Albarn, well, it ought to be.