It seems a fairly fruitless affair devoting another article to what a huge loss Kurt Cobain was to music and the social impact that still resonates today, but it's hard to really get a grip on the importance of this release - even 17 years after the event - without mentioning the underlying mood behind the scenes of the Nirvana camp at the time. The fact was the band had been elevated to a status beyond anybody's anticipation, least of all Cobain himself. Rumours of heavy drug use, family turmoil and inter-band strife had dominated the press and many doubted whether the band's planned third album would ever materialise.

By the time they took the stage at the Reading Festival in 1992, they were one of the biggest bands in the world, and they couldn't have seemed less comfortable with it. It's up for debate whether Kurt ever wanted the fame that came with the 'spokesman for a generation' tag forced upon him by MTV and the music press, however, the level of pressure that built was obviously taking its toll. Perhaps having as much recognition as peers Mudhoney or Tad would have been acceptable, but to suddenly be playing in front of over 60,000 people was a bit too much. They had propped up Chapterhouse on the bill at the 1991 festival for Christ's sake.

It's therefore practically a miracle that Nirvana ever made it to the stage for their seminal 1992 performance, now released on DVD for the first time (officially) after 17 years in the wilderness. Years of watching clips from the show and listening to dodgy bootleg recordings have done nothing to dull the impact of actually seeing it properly recorded and mastered, making this release a genuine event. The quality isn't perfect by any means - the camera angles seem a bit fixed compared to modern performance films, and it's amazing to see how far festivals have come on in a relatively short space of time (no screens, archaic lighting) but these are very minor niggles about what amounts to a truly essential purchase.

The gig itself is electrifying. From the moment long term confidant, champion of the band (though some would say sycophant) and Melody Maker journo Everett True pushes Kurt on in a wheelchair ("with the support of his friends and family, he's gonna make it" quips Krist Novoselic) to the final act of onstage destruction, it's hard to take your eyes off the screen for a minute. The band blast their way through ninety minutes, playing 25 tracks taken from all three of their albums, as well as throwing in a few B-Sides and barely stopping to breathe in between. There are beautiful moments that have since gone down in history - Kurt dedicating 'All Apologies' to newborn Frances Bean and getting the crowd to chant 'We Love You Courtney' is genuinely affecting, rather than vomit inducing - but mainly this is all about an enthralling spectacle.

The tracks from Bleach (including 'School', 'Blew' and 'Negative Creep') have a raw power with Dave Grohl drumming on them, something that Chad Channing could never quite muster, whilst tracks from Nevermind receive the rapturous response that you would expect from an album that was shifting around 200,000 copies a day for a while. 'Smells Like Teen Spirit', far from the millstone that it seemed to have become for the band is phenomenal, and the new songs ('Tourette's', 'All Apologies' and 'Dumb') hint at the brilliance to come.

But the fact is, everyone knows the songs already, and this is about a swansong (in the UK at least) - a testament to a hallowed musical time. It's about the hope that the performance brought - that maybe everything wasn't as bad as we had read - and the sad realisation that we now know that this was an anomaly, that the pain behind the scenes really was too much for Cobain to bear long term.

At the end of the gig, we see the band leave the stage and sign a few autographs for fans. Kurt, cigarette in mouth, agrees to meet a young fan suffering from leukaemia and advises him "don't start smoking" as he signs a piece of paper for him. It's a lovely moment tinged with sadness, as you see in his eyes that there's probably something terminal sat inside of him too.

There are arguments about why this performance has taken so long to be put out officially, but there is no argument at all as to its importance. This is probably as essential a music release as anything of the last 20 years.