By 1969 The Beatles were tired of being The Beatles. They had tried to recapture the magic of their early days by attempting to write and record an album of music that they could take to the stage, but the experience only served to illustrate how broken they were as a unit. It was decided that they would go back into the studio and record one final masterpiece so they could go out on a high note. George Martin was convinced to return as producer, and the band created Abbey Road. This was also The Beatles' last chance to get clues to their fans.
Lyrically there isn't a lot in the way of clues. One of the clues is sung by John during Come Together. He sings the words "One and one and one is three", which some interpret as revealing that there are only truly three Beatles.
A more obscure clue is in the song Sun King. The Sun King in French history was Louis XIV, and in Alexander Dumas' Louis is replaced by his twin brothers. Is it possible that the band is referring to Paul's replacement by a look alike?
The most compelling evidence of Paul's death is found all over the cover. The band is depicted walking across the street, and Paul is walking out of step with the other three. He is also barefoot, and allegedly some cultures buried their dead without shoes. He's also carrying a cigarette, which are sometimes referred to in British slang as "coffin nails".
Then there's the procession, which some people feel depicts a funeral procession. John is dressed in white, symbolizing the clergy, Ringo is dressed in black, symbolizing the undertaker, and George is dressed in work clothes, symbolizing the grave digger.
In the background we can see a Volkswagon parked close by. The license plate says LMW 28IF. Some interpret this to mean Paul would have been 28 had he lived, while others would argue that he would actually have been 27. Some cultures begin counting birth years at 1 from birth, which technically would make 28 the correct age.
The Beatles, knowing this would be their last chance to tell the truth about what happened to their fallen bandmate, also included clues on the back cover of the album. The first clue deals with the crack running through the band name. Some feel this indicates that the band was no longer intact after Paul's death.
To the left of the band name there are eight dots. Some believe these actually make the number three, which creates "3 Beatles" across the back of the cover.
Then to the right of the band name there is a shadow that is in the form of a skull. Is this meant to depict the skull of fallen Beatle Paul?
By the time Abbey Road hit the streets in September of 1969, The Beatles were essentially over as a functioning band. It wouldn't be long before the clues would all be discovered, however, so their fans could finally know the truth about Paul McCartney dying and being replaced by William Campbell, a Canadian. There was no need to release any further clues.
Still, they released more clues in their solo material.