IT was 40 years ago today that a genuine phenomenon was let loose on the world when Saturday Night Fever had its world premiere in Hollywood.

Two days later it opened to rave reviews across the USA and then in a carefully choreographed sequence, cinemas across the world began to show the film which defined an age – the disco era.

The potential audience had already been softened up by releases of the Bee Gees’ music for the soundtrack, most of which the three brothers Gibb – Barry, Robin and Maurice – claimed they wrote in a weekend.

When the film came out, audiences flocked to see it despite the fact that it was rated R in the US and X here by the censors – mostly for the strong language – meaning no-one under 18 should actually have been able to see it. Amended versions were later released and the film just kept on growing in popularity – it would eventually take

$300 million at the box office having been made for less than $4m.

DID IT START THE DISCO CRAZE?

TODAY’S younger generations might think so, but ask any old dad dancer and he will tell you that disco was very much a craze that dates from the late 1960s and early 1970s. Indeed disco seemed to have peaked and was on the wane until Fever came out and rebooted the whole culture, bringing in a new fad for competitive disco, not to mention white suits and raised heels – for the men, that is.

Its influence on everything from music to film and fashion cannot be understated.

THE GENESIS OF THE MOVIE?

THE Bee Gees’ producer Robert Stigwood was on a disco high after the Gibb brothers had a smash hit with Jive Talkin’ in 1975, which put them back at the top of the charts after several years in the doldrums and which they followed with You Should Be Dancing.

The inspiration for the film came from Stigwood’s determination to make a disco movie but it was a specific article in the New Yorker magazine in 1976 which inspired Stigwood and writer Norman Wexler. The article “Tribal Rites of the New Saturday Night” was about the New York disco sub-culture based around the 2001 Odyssey club in Bay Ridge, Brooklyn. The British writer Nik Cohn later confessed that he made the whole thing up.

Vincent in the story became Tony Manero in the film, and 23-year-old television star John Travolta was signed to play him.

At the last minute John Badham replaced the original director and proved an inspired choice. The rest, as they say, is history.

REMIND US OF THE PLOT?

TONY Manero (Travolta) is a delayed adolescent working-class Brooklyn kid in a boring job whose only joy in life is dancing at the local disco club – 2001 Odyssey, as in real life and Cohn’s story. There’s a subplot about his father Frank Snr (Val Bisoglio) being Italian and racist, and his brother Frank Jr (Martin Shakar) quitting the Catholic priesthood, but that all just got in the road of the music.

Abandoning his friend Annette (Karen Pescow), Tony hooks up with a classy dancer, Stephanie Mangano (played by Karen Lynn Gorney) and they practise hard and win the club’s dancing contest, only for Tony to realise a Puerto Rican couple were better. He gives them the trophy and stomps off with his mates who are in a fight with a local gang.

It all ends very messily, with Annette being raped and Tony’s friend Bobby C (Barry Miller) falling to his death from the Verrazano-Narrows Bridge that links Brooklyn to Staten Island. Having split with Stephanie, Tony goes off to Manhattan to be reconciled – and set up the sequel Staying Alive.

IT WAS ALL ABOUT THE MOVES AND THE MUSIC, WASN’T IT?

HATS off to you if you remembered the basic plot, but the scenes which made the film so vastly popular are all on the dance floor where Badham and choreographer Lester Wilson made a star of Travolta dancing to the soundtrack from disco heaven – the Bee Gees’ Stayin’ Alive, How Deep is Your Love, You Should Be Dancing, Jive Talkin’, More Than a Woman and Night Fever, plus If I Can’t Have You by Yvonne Elliman, Boogie Shoes by KC and the Sunshine Band and the instrumental that everybody remembers except for the name – A Fifth of Beethoven by Walter Murphy and the Big Apple Band.

WHAT HAPPENED TO THOSE INVOLVED IN THE MOVIE?

BARRY Gibb is the only surviving brother and this year received the tributes of the crowd at Glastonbury where he sang his own hit song Islands in the Stream.

Lester Wilson died of a heart attack cause by complications of Aids in 1993. One of his last films was Sister Act starring Whoopi Goldberg.

Robert Stigwood went on to make Grease with Travolta and Olivia Newton-John and Evita with Madonna and then had a long career in films and musical theatre before dying last year at the age of 81. Now 78, John Badham made War Games and Stakeout and is still directing in television.

Most of the acting cast stayed in work for many years but only Travolta became, and remains, a star who proved himself a fine actor in films like Pulp Fiction and Get Shorty. A scientologist, Travolta lost his 16-year-old son to a seizure in 2009. He has been married to actress Kelly Preston for 26 years.

Disco “died” in the 1980s but every so often enjoys a revival. Go to a retro disco night and you can bet there will be men

in white suits, the symbol of Saturday Night Fever.