American Pie is one of those timeless songs that seems to have been around forever, yet little is really understood about the meaning behind the seemingly complex lyrics that Don McLean wrote. The song has been covered by no less than Madonna (a far shorter version), yet it remains a mystery as to what it is actually referring to throughout the original track's eight-minute duration. That is until now, when the original manuscript is to be sold at auction in April.

The original song was released in 1972, reaching number one in the US charts and number two in the UK, with a reissue in 1991 climbing as high as number 12.

It is regarded as the folk rock McLean's signature tune and greatest creation by many, featuring on several lists of the songs of the century. Fans and critics in equal measure have long contemplated the interpretation of the lyrics, although the man himself has been generally reticent when asked to comment, only letting it be known that the frequent mention of "the day the Music died" is a reference to Buddy Holly's death in a plane crash in 1959.

McLean has long since recognised the importance of the track and worth to himself, flippantly commenting in 1991 that as a result of the song "I never have to work again." He kept the mystery behind the lyrics ongoing when asked by Reuters to comment on the forthcoming auction of the manuscript, merely letting it be known that it "will divulge everything there is to divulge."

There seems to be no shortage of potential bidders when the auction starts at Christie's, with estimates as to its worth putting the figure as high as $1.5 million (approximately £1 million).

Whoever the successful buyer proves to be, they will purchase for themselves 16 pages of typed and handwritten notes that accompanied the song when it was written in 1971.

As for the potential meaning behind the various references made in the song, many have hypothesised that they commonly refer to McLean's musical contemporaries and influences.

"The jester" is thought to be Bob Dylan, whereas mention of the "coat he borrowed from James Dean" could imply the cover of the Freewheelin' album. "King and queen' seems to offer a number of meanings, perhaps to Pete Seeger and Joan Baez, or maybe to Elvis Presley and Aretha Franklin. "Sergeants" could be a 'nod' to the Beatles' classic Sgt Pepper's album, while "eight miles high" could refer to The Byrds' hit.

There is no doubting the importance of the track to American fans of McLean's music though, as the song was made "Song of the Century" by the Recording Industry Association of America and the National Endowment for the Arts, besides being found a place for in the Grammy Hall of Fame.