Image copyright CENTRAL PRESS/GETTY IMAGES Image caption The show broke more new ground by employing a predominantly young cast Image copyright CENTRAL PRESS/HULTON ARCHIVE/GETTY IMAGES Image caption From top to bottom: Actors Peter Straker, Paul Nicholas, Annabel Leventon and Oliver Tobias during rehearsals
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 .