It was exactly 60 years ago that the Beatles arrived in Australia. For those of us who weren’t there – perhaps even those lucky enough to see Taylor Swift’s Eras tour – it’s hard to fathom the level of hysteria that accompanied their 1964 tour: in Adelaide 300,000 people lined the streets to welcome the band on 12 June – the largest crowd ever to greet the Fab Four.

Like Swift, seemingly every waking moment of the Beatles’ tour was dissected; editors were savvy enough to know just mentioning their name was a way of increasing circulation. Now that historic fortnight in Australia and New Zealand has been exhaustively documented in a new book by Greg Armstrong and Andy Neill, When We Was Fab.

Both authors are, naturally, serious Beatlemaniacs – especially the voluble Armstrong, co-host of Let It Be Beatles, the world’s longest-running Beatles radio show. On our Zoom call, various pieces of memorabilia are arranged behind him (I’m not remotely in his league, though he quickly spots a box set of the group’s recordings on a record cabinet behind me).

When We Was Fab is immense: a 160,000-word coffee-table tome, stuffed with previously unpublished photographs, press clippings and original documents, undergirding more than two decades of research. “I think that we just deserved a big, proper book on this tour,” Armstrong says. “It was their first world tour, and the story hadn’t been told before properly.”

In his 1953 novel The Go-Between, LP Hartley famously observed that the past was another country; they do things differently there. Australia and New Zealand did things very differently in 1964, and the Beatles’ tour marked a cultural inflection-point – a decisive “before” and “after” moment.

Australia, especially, was censorious and insular. One academic of the time noted that it had preserved many of the attitudes and standards of mid-Victorian Britain. Books were routinely banned; a letter to TV Week printed in When We Was Fab laments that “rock’n’roll indicates the extent to which two world wars have lessened family discipline”.

Nowadays it might seem quaint that the Beatles – whose music remains celebrated for its optimism, humour and generosity of spirit – could be the subject of such a moral panic, particularly when compared with the darker musical forces that would follow them: the Rolling Stones, the Who and the rest.

But the Fab Four were, first and foremost, a follicular menace. “It seems ludicrous by today’s standards, but it was all about the hair,” Neill says. “I mean, the Beatles dressed smartly, but their hair was scandalously long. We could have literally filled an extra book with letters to the editor by people who were just completely apoplectic about their appearance.

“That just shocked them to their foundations. But the other thing was the effect that the Beatles were having on their children – as soon as they knew the Beatles were going to be touring, these kids were prepared to camp out on the street for days on end to make sure they got tickets … It was literally the start of the generation gap in Australia.”

That the Beatles came to Australasia at all so early in their career, at the crest of Beatlemania, remains a curiosity. The group themselves barely made money from the 20 shows they played, having been contracted before their asking price skyrocketed. Had it not been for the foresight of promoters Kenneth Brodziak and Dick Lean Jr, the tour would probably not have happened.

Armstrong points out that both Australia and New Zealand were, and remain, Commonwealth countries. Moreover, this was the era of the assisted passage migration scheme, attracting more than a million “Ten Pound Poms” to Australia between 1945 and 1972. (It was also when the White Australia policy was still in full effect.)

That the Beatles would tour an Anglophilic, postcolonial country like Australia makes more sense in this context, especially given that television and rock’n’roll were still relatively new phenomena at the time. Promoters were only just becoming aware of the then-untapped commercial market of teenagers who were primed for the group’s arrival.

And Australia and New Zealand were ahead of the curve – or at least the US – when it came to the Beatles. “We got Please Please Me issued in both countries; it did some business,” Armstrong says. “From Me to You did better business; She Loves You did great business. I Want to Hold Your Hand came out and went to No 1 in the first week … We were at the beginning of the story, and we were a few months ahead of America.”

Media hype, naturally, played a part: “Teenagers were seeing more of the Beatles than perhaps their mums and dads for a while,” Armstrong adds.

How does Swift’s ubiquity compare? Armstrong saw Swift’s concert in his home town of Melbourne in February, and is a fan: “I think she’s incredible. But she’s not the Beatles, and the times are so different. The Beatles broke ground. I’m not saying [Swift] is not breaking ground, but she’s in a different world.

“Anyone can stream it, whereas you had to go cough up your money, back in the day, to buy a single – if you were lucky – with your pocket money. If it was Christmas or your birthday you might have got an LP. But the volume of records that the Beatles sold – they were the bus, and everybody got on board.”

Swift’s live extravaganza eclipses the Beatles in at least one way. “It’s a big machine, there’s so many people on her entourage and the tours are huge,” Armstrong says. The Beatles had almost no one around them by comparison, a reflection of a more innocent era: “It was the old days, and there were probably half a dozen people involved.”

• When We Was Fab: Inside The Beatles Australasian Tour 1964 by Greg Armstrong and Andy Neill is out now (Woodslane Press, $69.99)