Dylan in Newport: The electric earthquake

Newly released footage shows how Bob Dylan's 1965 Newport gig shocked folk fans

One of the music world's most notorious performances is finally available in glorious monochrome. Bob Dylan's electric set at the 1965 Newport Folk Festival has gone down in history as the moment when the boy from Minnesota morphed from folkie to rock star, and teenage rock'*'roll became all-conquering rock music.

Now, we can judge his transformation for ourselves with the release of The Other Side of the Mirror. The film covers Dylan's three Newport performances, starting with his 1963 debut, then the next year, when he was seen as the spokesman for a generation, to that pivotal moment when he supposedly turned the music world upside-down by changing his acoustic guitar for an electric one and was booed off for his pains.

The director Murray Lerner has finally received permission to use the footage he'd shot in the Sixties, and he shows the film in its simple glory, with the focus rarely wavering from Dylan's face. This at a time when folk was at the peak of its influence in the US, and in 1963 its great young hope rode the wave with his second album, The Freewheelin' Bob Dylan. The following year he came out with The Times They Are A-Changin' and Another Side of Bob Dylan.

His final Newport show, though, is tied in with his 1965 album Bringing It All Back Home, yet there is no definitive agreement as to what transpired. What we see is the artist emerging in a leather jacket to perform "Maggie's Farm" and "Like a Rolling Stone". There have been suggestions that the audience was narked by the set's brevity, yet the booing carried on between songs. Others claim that they responded to poor sound quality, although look at daytime performances and you see people enraptured by Dylan's mere presence.

The young upstart was certainly distraught by the end and had to be coaxed back on stage, placating the crowd with some acoustic numbers. Was he crying, as some attendees have claimed? The footage says not.

Today, Lerner has strong memories of that evening. "Me and the lighting guy just looked at each other. I knew this was the beginning of a new musical culture, because the electric music was much more powerful – it could be used for good or bad. And people in the crowd felt the same way. Some cheered, some booed – but many were just confused."

It seems strange to imbue one performance with such significance, because Dylan was already moving away from folk, by cutting explicit political references. At his Newport debut, a fidgety naïf performs protest songs such as "Who Killed Davey Moore?" and "With God on Our Side", all pally with Joan Baez and Peter, Paul and Mary. A year later, still with Baez, he is singing the surreal "Mr Tambourine Man" and the more personal "It Ain't Me Babe".

"Like a Rolling Stone" had its live debut at Newport, but this six-minute monster had already changed the rules about what could be released as a single or played on radio. A month before, The Byrds had enjoyed a No 1 hit with their electric version of "Mr Tambourine Man". Elsewhere, The Beatles had already admitted Dylan's massive influence – and the first fruits of this would be heard later that year on the Help! soundtrack, in "You've Got to Hide Your Love Away".

Yet Dylan at Newport did have repercussions. For one thing, there was so little warning. Bringing it All Back Home had been an equivocal statement, with one side devoted to Dylan's electric sound and the other firmly acoustic. No one expected him to plug in at such an august institution. Lerner had gone there to shoot archive footage for the organisers, but returned because there was more to this event than music. "I realised it was the centre of the counter-culture. It expressed all the ideas of the youth at the time, everything from civil rights to anti-war protests. Folk just gave an outlet for self-expression. It had more trust and integrity than pop music."

Some of this footage appears in his 1967 Newport documentary, Festival, which includes the likes of Seeger, Johnny Cash and Son House. For one weekend, this was a non-profit venture that aimed to preserve traditions. All performers were paid the same $50 and played short sets that included workshops as well as headline slots – there were no stars.

But when Dylan closed his set with an acoustic guitar, he has the last word with "It's All Over Now, Baby Blue". This was not simple, if didactic, entertainment. This was unprecedented confrontation between artiste and audience of a kind that has echoed down the years, from Lou Reed to John Lydon.

Going electric enabled this idiosyncratic performer to stay ahead of his followers. At a time when output was controlled by a tiny number of managers and A&R men, Dylan showed he was above anything as straightforward as genres. Such a brave move explains why fans still hang on to his every utterance as performer, writer and even – on a syndicated radio show – disc jockey. Lerner explains: "Dylan was supposed to be the mirror for his generation, but he broke through that. He opened us up to things we'd never thought of before."

And while he had already planted the seeds for the rise of rock, the fallout from the 1965 show continued for years. Jobbing R&B guitarist Jimi Hendrix was inspired to expand his repertoire, covering "Like A Rolling Stone" and turning "All Along the Watchtower" into a psychedelic masterpiece. Gram Parsons applied what Dylan had done with folk to another genre and laid the foundations for country rock. His band, The Flying Burrito Brothers, covered "If You Gotta Go, Go Now", played by its writer at a Newport daytime session in 1965.

Although the folk scene withered, its ideals found their way into a broader-based counter-culture. Its social awareness and anti-corporatism underpinned much of the hippie explosion of the late Sixties.

From the UK folk scene, the backlash was immediate. It meant it would remain a fringe activity, marshalled by the genre police that insisted on ideological purity. It was only in the late Sixties that brave souls like the Incredible String Band bridged the gap between traditional song forms, global influences and psychedelia. Pentangle mixed blues and jazz with folk and the Strawbs worked with a young Sandy Denny, though it was really the Dylan-influenced Fairport Convention that electrified the UK scene with their rock arrangements of traditional material.

While many gigs aspire to legendary status – the Stones at Altamont, Sex Pistols in Manchester – none can claim the impact of that stage in leafy Freebody Park. Do look back, and see how much we owe.

'The Other Side of the Mirror' is released on 29 October