Forget 'Spinal Tap'. Lester Bangs was rock's most debauched chronicler, a writer who lived life at maximum volume. Now a new film celebrates his explosive career

When I was a journalist at the NME, thrilled to have my byline in the same paper that had once employed Julie Burchill, Nick Kent and countless other journalistic godheads, a colleague and I erected a rather pitiful monument to the paper's heritage that we named the "Wall of Rock".

When I was a journalist at the NME, thrilled to have my byline in the same paper that had once employed Julie Burchill, Nick Kent and countless other journalistic godheads, a colleague and I erected a rather pitiful monument to the paper's heritage that we named the "Wall of Rock".

Digging through a photo file labelled "past writers", we had unearthed countless images that summed up the long-lost professional ideal to which we aspired: ludicrously dressed hacks, their hair tousled into the style du jour, perched behind typewriters, most apparently in a state of advanced disrepair. This was the life! Copy filed on the back of cereal packets, midnight summits at Keith Richards' country estate, Benzedrine binges in the office - somehow, the regimented, increasingly corporate world into which we had crash-landed simply didn't compare.

For anyone consumed by such a vision, there was a set text. Given the beguiling title Psychotic Reactions and Carburetor Dung, it was an anthology of writing by a man described as follows: "The great gonzo journalist, gutter poet, and romantic visionary of rock'n'roll writing - its Hunter S Thompson, Charles Bukowski and Jack Kerouac all rolled into one." By a stroke of luck that lent his name an almost onomatopoeic quality, the author was called Lester Bangs.

He had died in New York aged 33, having overdosed on a potent downer called Darvon. Prior to that, he had - in cahoots with a gang of compadres known as "The Noise Boys" - established a style of writing that is now all but extinct. It was reckless, honest, self-indulgent, riven with contradictions - and always suffused with the idea that, to use John Lennon's words, there is nothing conceptually better than rock'n'roll. Dipping into Psychotic Reactions, it became instantly obvious that Bangs had the rare gift of encapsulating in prose what it feels like when you hear a truly fantastic (or heart-stoppingly awful) record.

For one reason and another, this year has seen Bangs' legend loom larger than ever. In July, the American journalist Jim DeRogatis published Let It Blurt, a Bangs biography that managed the feat of being both frenziedly celebratory and poignantly affecting. Six months on, Bangs has been brought to the big screen, thanks to Cameron Crowe's autobiographical movie Almost Famous, based on his teenage experience of 1970s rock journalism, which opens the London Film Festival tomorrow.

Crowe - who long since made the jump from music hackery to Hollywood - began writing when he was 15. At the time, Bangs was an editor at Creem, a Detroit-based title that claimed to be "America's Only Rock'n'Roll Magazine". Crowe had sent some try-out work to Bangs, and duly received an assignment - interviewing the British band Humble Pie. He kept his age a secret, sneaked into the club where the band were playing, and filed the piece. Crowe's next stop was the more upmarket Rolling Stone.

The movie, in which Crowe is re-christened William Miller, shows the pair meeting in San Diego. Bangs - played by Phillip Seymour Hoffmann - is a fount of advice, both professional and personal. He warns the impressionable youth not to get seduced by the music-business circus - the booze, the endless junkets, the free records. He also tells him not to fret about the fact that his classmates hate him: "You'll meet them again, on their way to the middle," he advises. His role in the movie is as a kind of Merlin figure - the guru, the keeper of the flame.

Bangs - christened Leslie - was born in Escondido, California, in 1948. His father, prone to binge- drinking, died in a house fire when Bangs was eight. Soon after, he endured a period of sexual abuse at the hands of a middle-aged neighbour. Adding to the tumult, his mother was a Jehovah's Witness, and duly conscripted her son into the faith - which, he later claimed, explained his evangelical take on rock music.

After an adolescent visit to a Mexican brothel, he made a dramatic exit from his local Hall, when instead of repenting, he told the congregation what he thought of them. "You're all hypocrites! You say one thing and do another!"

By this point, he had long since fallen in love with American pop culture - and, more specifically, the music that lay at its heart. Having spent time at San Diego State College, training to be a teacher, he replied to an ad in Rolling Stone seeking new writers. No reply came for six months - until Bangs was called by a managing editor who soon placed him under the tutelage of the magazine's record reviews chief, Greil Marcus. "I like your writing," he told Bangs in 1969. "Write about whatever you want."

This elastic brief rapidly clashed with the economic realpolitik advocated by Rolling Stone's publisher Jann Wenner. Marcus was fired by Wenner after writing an entirely justified slagging of Bob Dylan's awful album Self Portrait; the magazine's recurrent financial difficulties meant that the goodwill of advertisers was crucial. In the words of Jim DeRogatis, "Wenner began admonishing his critics to 'just write about the music', which was generally interpreted as 'no-holds-barred criticism is no longer welcome'." Bangs, whose reviews tended to be scabrous, contrary, and about as far from industry-friendly puff pieces as could be imagined, started to see his copy fall on the spike.

It wasn't long before he found his spiritual home. Creem was based in Detroit, and more tuned in to Bangs' scattershot style. Initially housed in a three-storey loft building in one of the city's scuzziest districts, it eventually moved to a small town called Walled Lake, 30 miles north-west of the city. The staff shared living quarters, only adding to the frenzied air of their writing. Bangs' room-mate was one Dave Marsh, now a respected author. "We were so goddam communal," Bangs later remembered, "that I couldn't even go to the bathroom to jerk off without having Marsh bust in on me."

Creem published the work that sealed Bangs' reputation. His brilliant words, however, formed only part of his myth; as legendary was his appetite for drugs and drink, and his consequently dissolute lifestyle. At college, he had discovered a cough remedy called Romilar, which if imbibed in sufficient volume caused hallucinations. He was also keen on Quaaludes, meta-amphetamine, and swallowing the ephedrine-soaked wicks from nasal inhalers. With booze added to the stew, it was little wonder that he had little interest in such trifles as tidiness and personal hygiene.

His writing, thankfully, was the stuff of wonder. Words like "gonzo" do him a disservice: frequently, his words burned with a fierce moral sense, or a passionate belief in the good that rock music had done the world, or both. That said, any Bangs beginner is best advised to start with his more comedic pieces - exemplified by the string of articles that arose from his love-hate relationship with Lou Reed.

The ex-Velvet Underground singer - who, as such, was idolised by Bangs - spent the Seventies flitting between music of brilliance and spectacular awfulness, while turning himself into an exemplar of the drug-strewn demi-monde. Whenever Bangs interviewed him, he had no fear of calling Reed to account- and his subject seemed to enjoy their encounters. An excerpt from one of their face-offs, in 1975, proves the point:

Bangs: "Do you ever resent people for the way that you have lived out what they might think of as the dark side of their lives for them, vicariously, in your music or your life? Like, I listen to your records: shootin' smack, shootin' speed, committing suicide."

Reed: "That's three per cent of a hundred songs."

Bangs: "Like, with all this decadence and glitter shit - none of it would have happened if not for you, and yet I wonder if you..."

Reed: "I didn't have anything to do with it."

Bangs: "Bullshit, you started it, singing about smack, drag queens, etcetera."

Reed: "What's decadent about that?"

Bangs: "Okay, let's define decadence. You tell me what you think is decadence."

Reed: "You. Because you used to be able to write and now you're just fulla shit."

"What other rock artist," wrote Bangs, "would put up with an interview, read the resultant vitriol-spew with approval, and then invite me back for a second round because of course he's such a masochist he loved the hatchet in his back?"

Interviews like that have long been consigned to history - the record companies are too protective; the artists both paranoid, and conscious of their ability to secure nothing but vapid praise. Bangs saw that coming - when he relocated to New York in 1976, he saw that the launch of People magazine, with its emphasis on "celebrity", and antipathy to anything that could be considered criticism, had established a new journalistic paradigm, and his approach had fallen from grace.

He began making music - rough-hewn, punky stuff, full of lyrics that were occasionally as inspired as his writing. He also freelanced for the Village Voice, and saw his byline return to Rolling Stone. Just prior to his death, he was making long-overdue moves into the world of "serious" novel-writing. Watching Almost Famous, it's hard to avoid the conclusion that when music criticism left the Bangs approach behind, it lost something absolutely vital.

"There's no question about it," said the British journalist Mick Farren, himself an advocate of the no-holds-barred school. "In the field of journalism - forget about rock journalism - he broke ground that has now been concreted over."

'Almost Famous' is at the Odeon Leicester Square on 1 Nov, and on general release from 26 Jan