Imagine there’s no Beatles. It’s easy if you try.

How would the world have looked without the Fab Four? That is the question posed by Richard Curtis’s new film, Yesterday. Pop, protest and the sexual revolution might have been very different. When you hear Beatles, you immediately think insects. Oasis is just "an isolated area of vegetation in a desert". Meanwhile, Coldplay's Fix You is considered one of the greatest songs ever written. And cigarettesA thin tube of paper containing tobacco, which is then smoked. ? Never heard of them. This is the alternate universe imagined in the new filmn Yesterday, out in cinemas today. It is about a British songwriter called Jack Malik who wakes up and realises that he is the only person who remembers the 1960s' Liverpool band, The Beatles. So, naturally, Jack steals their songs and becomes an international pop sensation - with a little help from his friend Ed Sheeran, who advises Jack: "Song title: Hey Dude." The film is written by Richard Curtis (of Notting Hill and Love Actually fame), and directed by Danny Boyle (the man behind Slumdog Millionaire and both Trainspotting films). But, music aside, the fictional world of Yesterday is not so different from our own. Curtis says he preferred to focus on a love story, rather than on how The Beatles "probably changed our whole culture". Would history really have been the same without the world's biggestThe BBC and Sky have paid millions of pounds for the deal, which will go towards supporting players and clubs in the league. boy band? Certainly, pop music would have sounded different. "Their albums tied together the various strands of 60s' pop," writes The Guardian's music critic Alexis Petridis. Bob DylanAn American singer and songwriter who released his first album in 1962, aged 20. Dylan was awarded the Nobel Prize for Literature in 2016.'s lyricism; pop psychedelicsDrugs that can change your perceptions, for example causing hallucinations.; African-American rock 'n' roll: these styles would have remained disparate and scattered, rather than coalescing into a "world-shaking force". Music journalist Peter Doggett suggests that music would not have played such a big role in teenage rebellions in later decades. Instead of punk or rap music, he imagines a world where "the real rebellions are elsewhere - in fashion, art, folk music and poetry - and none of them impinge on pop". In 1968, The Beatles travelled to India and took up yoga and meditation. Without the group's interest in these Eastern practices, they may never have crossed over into mainstream Western culture. Lady Gaga has even credited The Beatles with "the birth of the sexual revolution". Would millions of young women have thrown off old ideas about sex had they not been so captivated by four, handsome lads from Liverpool? Times of trouble? The real question is: can one person (or four people) change the course of history? It was certainly magical when two of the world's greatest songwriters collaborated: John Lennon's out-of-the-box creativity coupled with Paul McCartney's focus on detail produced music that was unique and unequalled. But history is long and winding, and all of us play a part in building culture. The anti-war movement, the sexual revolution, the influence of psychedelic drugs: all these events shaped the 1960s - and the decades that followed - with or without The Beatles. They just happened to sound a little different. KeywordsCigarettes - A thin tube of paper containing tobacco, which is then smoked.