©Bob Kreisel/Alamy Two hippies photographed in a doorway in Haight-Ashbury in 1969

“Never trust a hippie” was one of the more polite slogans that reverberated around the sun-soaked streets of London 40 summers ago, as punk first announced itself to a startled public. The wording is revealing. Young punks did not merely detest the aimless musical doodles and relentlessly earnest platitudes that dominated the culture of the previous decade; they felt betrayed by them.

The 1960s were supposed to be about the destruction of the establishment and the creation of an alternative set of values, or so it was said. Instead of which, the decade’s naive protagonists were subsumed by the very people who were supposed to be their enemies. Punk’s ugliness and anger came from a sense of feeling let down. Its brash cynicism was a spiteful coda to the collapsed ideals of youth culture.

But in the very months in which punk’s zesty iconoclasm is being commemorated, a new exhibition at the Victoria and Albert Museum is about to challenge that critique. In You Say You Want a Revolution? Records and Rebels 1966-70, opening next month, the achievements of the late 1960s are presented as lasting and important. Curated by the same team who masterminded the museum’s David Bowie Is . . . show, the new exhibition will argue that the five years under review sparked a “fundamental shift in the mindset of the western world”.

The show’s title comes from The Beatles’ 1968 song “Revolution”. It was an uncharacteristically tentative ideological statement from its writer John Lennon. When the song was released as a single in the summer that followed one of history’s most turbulent springs, Lennon sought to distance himself from political hardliners.

“But when you talk about destruction, don’t you know that you can count me out?” he sang emphatically.

Months later, shaken by accusations that he had betrayed his revolutionary principles, he hedged his bets when he recorded the song again. In the version of “Revolution” on The Beatles’ White Album he sang: “But when you talk about destruction, don’t you know that you can count me out, in?”

Even the greatest artists of the 1960s weren’t sure which way the world should be going. With the benefit of hindsight, and the help of a killer soundtrack, the V&A show aims to be a postscript to those confused times. Much of the exhibition is devoted to San Francisco, one of the vibrant and intellectually dominant cities of the late 1960s. To visit the city today is to see the germination of many of the seeds sown during that era.

In Haight-Ashbury, the epicentre of the hippie moment in the summer of 1967, Stan Flouride conducts “Flower-Power Walking Tours” around the now-gentrified neighbourhood.

His spiel is lively and full of well-rehearsed, waspish asides. He points to hippie-themed murals, drawn in 1977, on Belvedere Street.

“They are about the benefits of yoga, tai-chi, and the importance of fruit and vegetables,’’ he says drily, not needing to point out any more clearly their contemporary resonance. He gives a scholarly explanation for the hippie scene starting in these streets: it was a combination of beatnik culture and the high integration of African-Americans in the neighbourhood after the second world war, creating a tolerant and open-minded spirit. Flouride clarifies some terminology: “hippie”, he believes, was a derogatory term for youngsters on the fringes of the “hipster” scene, that term being reserved for white jazz fans.

A drawing of Jerry Garcia on a San Francisco pavement

The summer of love was also a summer of anxiety for straight America: in the CBS documentary The Hippie Temptation, aired in August 1967, the lugubrious presenter Harry Reasoner analysed the faux innocence of the movement. He accepted that the hippies wanted to be children again. “But people who grow beards and make love are supposed to move from innocence to wisdom,” he admonished. Interviewed in the film, Grateful Dead guitarist Jerry Garcia sets out his own aspirations: “A peaceful planet. An uncluttered life, a simple life, a good life. Thinking about moving the whole human race ahead a step.”

The solemn, heritage vibe on Haight-Ashbury differs from the air of nostalgic kitsch in other 1960s celebrity hang-outs such as London’s Carnaby Street. There’s still a moral dimension celebrated here: more than one of the tourist shops sells a small yellow badge proclaiming: “The hippies were right”.

If not right, they were certainly prescient. Around the dopey guitar playing and facile slogans, a certain entrepreneurial spirit was making itself felt on America’s west coast.