Image copyright Don McLean/Capitol Records Image caption A long, long time ago... Don McLean says his original lyrics reveal "everything there is to know"

As the original manuscript for Don McLean's 1971 classic is sold at auction, fans may finally discover what his "Song of the Century" is really about. So what are the popular theories?

When people ask Don McLean what does American Pie really mean, he likes to reply: "It means I never have to work again."

His eight-minute-long "rock and roll American dream" became an anthem for an entire generation - who memorised every line.

Their children in turn grew up singing it - fascinated by the mysterious lyrics with their cryptic references to 50s innocence, the turbulent 60s, and 70s disillusion.

Who broke the church bells? Who was the jester who sang for the king and queen? And what really was revealed "the day the music died"?

Image caption American Pie is the longest song ever to top the Billboard Hot 100, at eight minutes and 36 seconds

There are fan websites entirely dedicated to solving these mysteries, where literary detectives pore over the clues, line by line.

The song's 69-year-old architect has always remained tight-lipped.

But now at long last, the inspirations behind his Song of the Century are to be revealed after McLean put his original manuscript up for auction.

These 16 pages of handwritten notes, which have lain hidden away in a box in his home for 43 years, were sold for $1.2m (£800,000) at Christie's in New York, to an anonymous bidder.

Media playback is unsupported on your device Media caption Will these scribbles decode the puzzle of American pie?

But for McLean aficionados there is a greater prize.

The drafts, unedited, reveal the creative process behind American Pie "from beginning to end", according to Tom Lecky of Christie's.

"You see great moments of inspiration, you see him attempting things that then didn't work out. The direction that he was going in that he then didn't want to follow.

"Those words that we all know so well weren't fixed in the beginning."

Image copyright don mclean Image caption McLean's original notes, unedited, are 16 pages long and give clues to his thought process

As the singer himself said recently: "The writing and the lyrics will divulge everything there is to divulge."

For McLean scholars with pet theories, there could be bad news on the doorstep. This could be the day that they die.

But before we sing bye bye, and in honour of the American Pie fans everywhere, the BBC News Magazine takes a nostalgic trip back through the song's six enigmatic verses, and the popular theories that have grown up around them.

"So bye-bye, Miss American Pie..."

Image caption Buddy Holly's death was a "personal tragedy" for the 12-year-old McLean

Contrary to popular rumour, "American Pie" was not the name of the plane that rock and roll legend Buddy Holly died in, says Jim Fann, author of Understanding American Pie.

Miss American Pie is "as American as apple pie, so the saying goes," he argues.

"She could also be a synthesis of this symbol and the beauty queen Miss America."

Either way, her name evokes a simpler, optimistic age and McLean bids her farewell.

"The day the music died" refers - of course - to Holly's untimely death on 3 February 1959, which McLean mourns as the end of the entire 50s era.

But if you think this is "what American Pie is about", you would greatly disappoint McLean, who is on record that his song has so much more to say in the verses that follow next.

"Do you believe in rock and roll? Can music save your mortal soul?"

Into verse two and the swinging 60s have arrived. "Faith in the music now replaces faith in God," Fann observes.

The religious imagery that emerges in the second verse becomes a powerful and recurring symbol of loss throughout the song.

From "the sacred store" to the broken church bells, from this point forward, "whatever is couched in religious terms can be seen as referring back... to the happier innocence and faith of the 1950s," says Fann.

The fickle girl who McLean saw "dancing in the gym" no longer cares for his "pink carnation and pickup truck", leaving him "out of luck".

Image copyright Hulton Archive Image caption Bob Dylan was McLean's "rolling stone" who ended up gathering moss

"When the jester sang for the King and Queen, In a coat he borrowed from James Dean"

Enter Bob Dylan, the court jester who becomes the revolutionary leader of the 60s generation, knocking Elvis, the king of the 50s, off his pedestal: "While the King was looking down, the jester stole his thorny crown."

The jacket Dylan "borrowed from James Dean" can be seen on the iconic cover sleeve of his 1963 album The Freewheelin' Bob Dylan.

But by the end of the decade, we see that Dylan's "rolling stone" is gathering moss, in fat quantities.

"The old cliche is turned on its head, reflecting how the wholesale rejection of conventional values had become commonplace by 1970," as Fann interprets.

Image copyright Hulton Archive

But if you think the case is closed on the true meanings in this third verse, think again - "no verdict" has been returned.

One alternative theory casts McLean's "King and Queen" as Pete Seeger and Joan Baez, the folk giants of the early '60's whose crown Dylan ultimately stole.

Another has the monarchs as President John F Kennedy and the First Lady Jackie Kennedy, with Lee Harvey Oswald as the "jester who stole his thorny crown".

Whichever way you peer at it, "the world [McLean] once knew is changing," concludes Fann.

Image copyright keystone Image caption Was JFK the "king whose thorny crown was stolen"?

Image copyright BIPS Image caption The Beatles surpassed Dylan as the icons of the 60s generation

"Now the half-time air was sweet perfume, While sergeants played a marching tune"

As the 60s reach their turbulent climax in verse four, and nuclear tensions rising, the Beatles have become the "sergeants" leading the march of counter-culture, leaving Dylan behind as "the jester on the sidelines in a cast" after his near-fatal motorbike crash.

But just at the peak of the sweetly marijuana-perfumed Summer of Love in 1967, the tension boils over into civil unrest. "We all got up to dance, but we never got the chance," sang McLean.

He looks on as the "players try to take the field; But the marching band refused to yield".

There are almost as many theories for this line as the single has sold copies (more than three million in its first year). One has the marching band as the police blocking civil rights protesters, another as the Beatles preaching non-violence with their 1967 hit "All You Need Is Love".

"Do you recall what was revealed the day the music died?"

Image copyright Hulton Archive Image caption The Chicago police riot of 1968 saw violent clashes with demonstrators

This could be the song's most ambiguous line of all.

Some suggest it refers to a John Lennon and Yoko Ono album cover. Another popular theory is the Miss America contest of 1968 where feminist protesters had supposedly "burned their bras".

But the most likely reference, Fann believes, is the 1968 riot at the Democratic National Convention in Chicago, where police brutally cracked down on demonstrators.

What was revealed? "The dark underside of one of our most cherished institutions," he argues.

But perhaps "what was revealed" has nothing really to do with any of these events, and is really a harbinger for the tragedy that follows in the fifth verse...

Image copyright Hulton Archive

"And there we were all in one place, A generation Lost in Space"

A giant gathering of people, all high on drugs. It has to be Woodstock, right? Not so, say Pie connoisseurs.

The lyrics more closely match the tragic concert at Altamont Speedway in December 1969, where "Jack Flash sat on a candlestick".

Image copyright AP Image caption An estimated 300,000 revellers came to Altamont to see the Rolling Stones and Jefferson Airplane

"No angel born in hell could break that Satan's spell"

The Stones' frontman Mick Jagger really did appear on stage that night dressed in a flowing red cape, singing lyrics inciting fire and rebellion.

Meanwhile at the stage perimeter members of the Hells Angels motorcycle gang - hired as security - engaged in bloody clashes with the rioting audience.

Jagger was later accused of failing to halt the performance, infuriating McLean's narrator: "I saw Satan laughing with delight; The day the music died".

Image copyright AP Image caption Mick Jagger looks on as the Hells Angels deal with a crowd member. The show continued

Just as Woodstock was heralded as the landmark of the counterculture movement, "Altamont was the event that signalled its demise. Reality steps in," says Fann.

The tragedy served to finally "burst the bubble of youth culture's illusions about itself," wrote Todd Gitlin, an eyewitness, in his book The Sixties: Years of Hope, Days of Rage.

And in the final verse of McLean's parable, when he "goes down to the sacred store, where I'd heard the music years before" he finds that sadly:

"The man there said the music wouldn't play"

And these words are not just symbolic. "Literally, the music stores that had once provided listening booths for their customers were by this time no longer offering this service," writes Fann.

But even more so, "the cynicism of this generation had annihilated the innocent world the narrator had grown up in."

That kind of music simply wouldn't play any more.

Forty-three years later, it would be nice to think that - whatever the revelations to come from McLean's original scribbled notes - they will not burst the bubble for the millions of fans who still dream of Chevys, whisky and rye.