Woodstock: 40 Years On: Back to Yasgur’s Farm

Forty years after the fact, the dry statistics almost obscure the more romantic aspects of three days on Yasgur's farm in August 1969. Yes, the organisers expected a fraction of the half-million-strong crowd that turned up. And yes, the line-up features some huge names, many of whom (as with Live Aid, 15 years later) became superstars following their performances. But what made what was described by Tommy James' manager as just a "pig farmer in upstate New York that wants you to play in his field" affair so special? This definitive six-CD set may be the final word, but it only tells half the story.

Much of the event's enduring legendary status is down to Michael Wadleigh's documentary film and an editor by the name of Martin Scorsese. Their on-screen eye candy meant that a large-scale media event easily became subject to retrospective mythologising. It certainly seemed that way to Neil Young, who refused to be filmed.

The music is, on the whole, a ragbag of mismatching parts and ropey performances - no amount of hazy nostalgia is going to make John Sebastian seem cool. And there's a reason why The Who sound a little testy: nobody who'd imbibed so many chemicals and then been forced to perform to a field full of semi-comatose hippies at four in the morning is going to sound on top form, unless they're either a jazz musician or Jimi Hendrix (who actually played as the festival was packing up on the Monday, making his turn even more miraculous).

Great moments? Joe Cocker is transcendent, and Santana rightly deserved a career boost, their Latino stew adding colour to the muddy brown weekend. The lack of diversity is a more accurate pointer to the state of music at the end of the 60s. Despite the presence of Ravi Shankar, the counter culture's standby when ethnicity was needed, this is a bill high on mostly folk, rock and blues. The only funk and soul was provided by Sly Stone.

And there are slices of self indulgence here to test even the most stoned: Johnny Winter's Mean Town Blues, for example, seems to go on for hours. The Grateful Dead, never ones to allow themselves to be predictable, turn in a lengthy (what else?) Dark Star. It's a performance that's particularly amusing when juxtaposed with the tight, gritty swamp rock of Creedence Clearwater Revival. God bless John Fogerty, indeed.

The 'wisdom' dispensed by Jerry Garcia, Chip Monck and Country Joe McDonald about the various dubious types of acid sums up the contrary logic while still making you misty-eyed for innocent belief in the power of positive thinking. And essentially that's what Woodstock represents. More than the music or the visuals, its importance stems from the fact that so many people put up with conditions that would appal the modern festival-goer and still came away believing that they could change the world. Far out.