This article is part of Yahoo's 'On This Day' series
There have been a number of people dubbed the “fifth Beatle”.
The list includes those intrinsic to the success of The Beatles, including manager Bruce Epstein and producer George Martin.
Musicians such as drummer Pete Best, bassist Stuart Sutcliffe and keyboardist Billy Preston, who all played in the band at some point, were also given the mantle.
But there is one name that makes conspiracy theorists prick up their ears, and the majority of Beatles fans shake their heads in disbelief.
And that name is Billy Shears.
To believers, not only was Billy Shears the fifth Beatle, he was a lookalike who had replaced one of the band’s members without the world’s knowledge.
It may seem remarkable now, but on this day 52 years ago, Paul McCartney was forced to deny that he was dead.
On 22 October, 1969, the Beatles bassist insisted he was very much alive.
When contacted on his farm in Scotland by Peter Brown, manager of Apple Records, who wanted a statement he could give to the press, McCartney reportedly replied: “Rumours of my death have been greatly exaggerated.”
Watch: Disney debuts trailer for upcoming Beatles documentary
The rumour, which began circulating in 1967, was that McCartney had died in a car crash on the M1 on 9 November the previous year, and that The Beatles had brought in a doppelgänger to replace him so as not to dismay their millions of fans.
The “Paul is dead” urban legend, as it became known, went that McCartney had been replaced by Shears, also known as “William Campbell”, purportedly an orphan from Edinburgh who the band trained to impersonate their famous bassist.
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One of the conspiracy theories claimed Shears was planted in the band by MI5.
Some fans believed The Beatles left clues in their music after McCartney’s supposed demise.
In their 1968 song, Glass Onion, Lennon sings: “Here’s another clue for you all / The walrus was Paul.”
In the song Strawberry Fields Forever, released in February 1967, conspiracy theorists claimed that, when played backwards, Lennon sings “I buried Paul” in the track’s final section. Lennon later said the words were “cranberry sauce”.
But when the Abbey Road album was released in September 1969, it wasn’t the songs that came under scrutiny.
Instead, those who believed in the “Paul is dead” theory couldn’t keep their eyes off the famous cover of McCartney, Lennon, Harrison and Starr on a zebra crossing in north-west London.
The cover was interpreted by some as a funeral procession, with Lennon as the heavenly figure dressed in white, Starr as the undertaker in black and Harrison as the gravedigger in denim. McCartney, out of step with the others and in bare feet, represented the dead body.
A Volkswagen Beetle in the background of the cover shot bore the number plate LMW 28IF - some fans thought it referred to McCartney’s wife, claiming it stood for “Linda McCartney Weeps” or “Linda McCartney, Widow”.
They also said the “28IF” was a reference to McCartney’s age if he had been alive (although he was actually 27 when Abbey Road was recorded and released). On the cover, McCartney, who plays guitar left-handed, holds a cigarette in his right hand, giving conspiracy theorists more reason to believe it wasn’t the real Beatle in the photo.
While the rumour of McCartney’s death had been floating around in music circles, it wasn’t until just before Abbey Road’s release that it started to really take hold.
On 17 September, 1969, the Drake Times-Delphic, a student newspaper at Drake University in Des Moines, Iowa, published an article titled “Is Beatle Paul McCartney Dead?”.
Nearly a month later, on 12 October, radio DJ Russ Gibb discussed the rumour with callers on Detroit station WKNR-FM. A listener to the show, University of Michigan student Fred LaBour, then wrote a satirical article for The Michigan Daily newspaper titled, “McCartney dead: New evidence brought to light”.
This became the source of many of ideas connected to the conspiracy theory, including the interpretation of the Abbey Road cover and William Campbell (LaBour later admitted: “I made the guy up.”).
The urban legend grew in the days that followed to the point where the band was forced to address it.
The band’s management called it “a load of old rubbish” on 21 October, the day before McCartney himself denied it.
A month later, Life magazine published an interview with McCartney from his Scottish farm - its cover read: “Paul is still with us”.
In the interview itself, McCartney, who had married Linda earlier that year, said: “Perhaps the rumour started because I haven't been much in the press lately.
“I have done enough press for a lifetime, and I don't have anything to say these days. I am happy to be with my family and I will work when I work.
“I would rather be a little less famous these days.”
In the end, the rumour didn’t do the band any harm - as Lennon had predicted, the urban legend gave Abbey Road a sales push, while sales of their previous albums also spiked.
In an interview with Rolling Stone magazine in 1974, McCartney recalled being asked about the rumour the previous decade.
He said: “Someone from the office rang me up and said, ‘Look, Paul, you’re dead.’ And I said, ‘Oh, I don’t agree with that.’”
In 1993, McCartney had his own fun with the rumour, calling his solo live album “Paul Is Live”, even spoofing the famous Abbey Road photo on its cover.
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