On 27 September 1968 the curtain fell on centuries of theatre censorship. Hours later, a cast of long-haired young actors took to the stage in a show depicting drug-taking, anti-war protests and shocking nudity. London's West End was never the same again.
Hair was a musical that placed the 1960s counterculture on stage. It thrust bisexuality, interracial relationships and the rejection of monogamy in front of audiences who had previously been "protected" from such taboo subjects.
In a theatre first, one scene featured the cast appearing from behind a sheet, fully naked and chanting the words "beads, flowers, freedom, and happiness".
Despite lasting just seconds, it was considered scandalous and resulted in many audience members walking out of the Shaftesbury Theatre, dinner jackets in hand.
Prior to the autumn of 1968, any reference to homosexuality, bisexuality and nude performances would have been considered too outrageous to be shown on a British stage.
Even something as seemingly harmless as a reference to Walt Whitman's poetry collection, Leaves of Grass, in John Osborne's play Personal Enemy, was banned because it was seen as a codified reference to homosexuality.
But as the Lord Chamberlain's powers of censorship - which dated back to 1737 - came to an end, the cast of Hair began preparing for its opening night.
The risqué show, written by out-of-work actors Gerome Ragni and James Rado, had already proven a hit in New York the year before.
A young David Bowie auditioned for a part - four times in total - but was never invited to join the London cast (he later attended a performance but reportedly came away "unimpressed").
The musical told the story of the "tribe", a group of politically active hippies living a bohemian existence in New York City.
Its main protagonist Claude, played by 23-year-old Paul Nicholas, lived a life characterised by the pursuit of love, peace and sexual revolution - but faced a battle with his family who wanted him to fight in Vietnam.
The hippies' long hair - and the title of the show - was a symbol of their defiance.
"You would have had to have your hair cut when going into the military and therefore the name Hair is highly symbolic," says Geoffrey Marsh, director of the V&A's Department of Theatre and Performance.
Nicholas, who along with Elaine Page and Oliver Tobias subsequently became a household name, still remembers the outrage the nude scene provoked.
"Fifty years ago there was no nudity in commercial theatre - so it was a big change," he said.
"But looking back, the 'shocking' nude scene which was widely spoke about wasn't even that bad - it was nicely done. It wasn't salacious or anything like that.
"But some people walked out of the theatre, you know, in disgust."
Annabel Leventon played Sheila in the original cast on the London stage.
"On the first night, and it never happened anywhere else in the world - as far as I know - the cast of Hair went out into the auditorium," she told BBC Radio 4's Woman's Hour.
"We danced in the aisles, sat on the audiences' laps, frightened them, and at the very end of the show we all ran out singing Let the Sun Shine In and went back on stage and the whole audience followed us [back on stage].
"That's when we realised the show made a greater change in Britain than anywhere else.
"Hair really shocked and changed the world of theatre forever."
Hair continued to strike a chord with audiences for the next five years.
This was despite opening to decidedly mixed reviews. WA Darlington, of the Daily Telegraph, had insisted he "tried hard" but found the evening "a complete bore".
However, the predominantly middle-aged white male critics were not the show's intended audience and it went on to run for 1,997 performances until 1973.
Simon Sladen, of the V&A Museum, said the show soon had an impact on the rest of the West End.
Once censorship was revoked, some playwrights and producers would "binge" on things that had previously been forbidden.
"The youth movement could finally come alive in the theatre - full of energy and vitality," he said.
"Hair was like a festival on the stage - an anarchic explosion of all things anti-establishment."
Nicholas, who met his future wife Linzi while working on the show, agrees.
"Everyone wanted to do a nude scene, or have the cast swear on stage," he said.
"It's as if they were getting it out of their system because we'd been suppressed for so long."