Watching the fabbest of all fours in their first US press conference, puffing away on cigs and deflecting inane enquiries, you feel proud to be a Brit. “Sing something for us!”

“No, we need money first.”

Could Justin Timberlake?or Julian Casablancas, for that matter?be half as sarcastic?

Imagine waking from a 40-year coma and coming afresh to these extraordinary scenes: four scouse charmers off the plane with their matching suits and Pan Am shoulder bags. Scratch that?it’s impossible, so indelibly are these images etched on pop’s collective unconscious. But watching the film that Albert and David Maysles made of The Beatles’ triumphant first visit to the Yew Ess Eh actually does make it all new. And incredibly exciting. And deeply touching.

One little-known but starkly significant fact: a short news piece about the Fabs was aired on the CBS network two days after the assassination of President John F Kennedy on November 22, 1963. Two months later, the group arrived at the just-renamed Kennedy Airport as literal saviours, scally angels sent from heaven to heal the seeping Dallas wound. (In one proto-Hard Day’s Night scene in The First US Visit, Paul wanders along a train compartment shaking hands and remarks, “This is like running for president.”)

Sure, screaming suburban girlies had accompanied every move Sinatra and Presley made. But Francis Albert and Elvis Aaron were all-American boys, more or less next door. The Beatles were funny aliens with “mop-top” hair and bad Liverpudlian teeth. And the whole of America fell in love with them.

Watching John, Paul, George, Ringo, Old Uncle Murray the K and all?in their Plaza suites, in their besieged limos, in the Twist-tastic Peppermint Lounge?it’s hard not to mourn the loss of their openness and genuine brotherhood. It’s also no wonder that the film was canned on account of A Hard Day’s Night, for The First US Visit feels like a cinema verite demo for Richard Lester’s capersome flick. Effortlessly unselfconscious before the camera, the group engage in amusing pranks and japes throughout.

Then there’s Brian Epstein, his fratefully posh and harrassed blonde secretary in tow, dictating telegrams and uttering “Gosh, fantastic!” on getting good news from London.

And let’s not forget the performance footage itself. Again, those of us d’un certain age can’t watch the iconic Ed Sullivan Show appearances and really ‘see’ them. They’re part of the furniture of our minds. At stage left is macho John, legs planted like trunks: at stage right stand Paul and George, thin and boyish as they harmonise at the same mic; behind his kit, Ringo is a grinning gnome. But I’d forgotten the divine “This Boy” from the Deauville on Miami Beach?what a great song.

It’s fitting that the Maysles Brothers documented the birth of the pop ’60s when you reflect that, five years later, they documented its bloody symbolic demise at Altamont.

“They’re four of the nicest youngsters we’ve ever had on our stage,” says the stiff Ed Sullivan before introducing the Fabs for the first time. After their third and final appearance that month, he commends them for their “conduct as youngsters”.

Up ahead lie Lennon’s FBI files and death at the hands of Mark Chapman: the Beatles’ American dream turned nightmare. For now, hold on to this magic place in the past, this amazing innocence before pop went sour.