Revealed: unseen pictures of The Beatles in America (and how they really got to No 1)

Highlights from hours of unseen fly-on-the-wall footage taken during the Beatles' crucial and chaotic first visit to America in 1964 are to be seen for the first time.

The sequences show John, Paul, George and Ringo bumbling, smoking, running and joking their way through hotel lobbies, corridors, train carriages and waiting rooms amid unprecedented scenes of pandemonium and adulation - a real version of the phenomenon later simulated for the film A Hard Day's Night.

The exceptionally candid footage, shot by the legendary team of Albert and David Maysles - who went on to make the Rolling Stones' Altamont movie Gimme Shelter - explodes the myth that the group's initial assault on the US market was stage-managed.

Forty years on, The Independent on Sunday can reveal how much coincidence and luck helped the leap from regional cult band to global phenomenon. The film itself was the result of a chance meeting, and we have learnt that the arrival of the single that "made" the Beatles in the US came about through a series of happy accidents.

The new Beatles film is extraordinary. In stark contrast to the slick, "on-message" films about rock and pop bands now the rule in an industry obsessed with image, the Maysles were able to film the band members wherever and whenever they wanted. Their black-and-white footage, shot over a few freezing February days - covering the band from their arrival at the newly renamed John F Kennedy Airport, a hectic train journey from New York to Washington, appearances on the Ed Sullivan Show, and their first concerts in the US - shows the raw, ad hoc nature of their early days.

The unseen scenes, to be released by Apple, the Beatles' company, as part of a 40th anniversary DVD package early next month, were shotfor Granada Television's World In Action. "One night at the end of 1962 I went to the Cavern Club to hear some jazz," recalls Dick Fontaine, then a young researcher with Granada. "When I got there they produced Lennon and McCartney to talk to me. Some- one at the club had said to them: 'A bloke from the telly's coming.' It was the week Ringo joined the band. John and Paul said: 'Come back and hear us', so I did, and I thought: 'Aha, here's my first film.'"

A year later, Fontaine heard from a friend, the band's photographer, that they were about to go to States. "I called an avant-garde film-maker, Ricky Leacock. He thought it was a dumb idea but suggested Albert and David Maysles. I phoned them in New York on a Wednesday, and Friday the band arrived. I asked them to start filming when the plane landed, and I met them there."

The resulting 45-minute film, Yeah Yeah Yeah!, edited and produced by Fontaine, was broadcast before the band's return to the UK on 22 February - itself an event of such import that Saturday afternoon's Grandstand was interrupted for live coverage from London Airport. Yeah Yeah Yeah! was the first cinéma vérité-style documentary - no narration, hand-held camera and close-up sound recording - on British TV. It elevated the Beatles to a cultural spectacle worthy of serious study. The Maysles made their own documentary on the visit, entitled What's Happening! The Beatles In The USA.

"Kennedy had been killed just two months before," says Fontaine. "The children of America were in trauma. That had a huge amount to do with what happened with the Beatles there. It was phenomenal, other-worldly."

"Having fun with a camera," Fontaine called it. New hand-hand 16mm recording equipment was used. "You could really film people's events and experiences without imposing yourself with lights and tripods and unwieldy equipment," Albert Maysles told the IoS last week. "We were paying attention to people's lives as they were lived. We stuck to our principle of not trying to change anyone's behaviour."

When the Beatles touched down at New York, "I Want to Hold Your Hand" had topped the US charts. Again, this was due to a chain of chance events, this time involving a woman who is one of the US government's most powerful executives. Elizabeth James Duke, now in charge of much of the US Health Department but 40 years ago married to a Washington disc jockey, Carroll James, told us the story as she was about to go into a meeting with George Bush.

"In late 1963 an American television newscast showed a phenomenon called the Beatles going on in England," recalls Mrs Duke. "I Want to Hold Your Hand", had been number one in the UK, but hadn't yet been released in the US. "The head of the company that owned the radio station, WWDC, had hired a new secretary," she said. "Turned out she had once worked for Brian Epstein, the Beatles manager. We had a friend who was a pilot on BOAC, and we thought we'd get a copy of it flown over from one of the secretary's friends in Britain. They would give it to the pilot, and the pilot would bring it to America, and he would play it.

"Carroll played it - on the hour, every hour for days. Capitol Records, who had the rights in America, went ballistic, they thought of suing us, but they moved forward their release date for the single." And that's what gave the Beatles their first US number one.