Paul McCartney's handwritten notes for best-selling hit, Hey Jude, are coming to Liverpool next week as part of a new exhibition.
The song, which sold more than 8m was The Beatles' most successful single, and tells the painful story of John's break-up with first wife Cynthia.
'The White Feather: The Spirit Of Lennon' exhibition, delves deep into the pop icon's family life.
Until now, his son Julian and ex-wife Cynthia's emotional story has remained largely untold.
But for the first time, Jerry Goldman from the Beatles Story has convinced the pair to open-up about their turmoil and tears in an on camera interview.
At the centre of the candid conversation is the back story behind Hey Jude.
Mr Goldman said: "You have no idea how personal this exhibition is.
"I went to Julian's pad in the south of France and got them talking to me.
"In the course of the conversations, I asked some really searching and personal questions.
"For example, when you see Cynthia talking about how she felt the moment Paul knocked on her door after her split with John, you can really see the emotions right there, clear to see."
McCartney had travelled down to Lennon's family home in Surrey after Cynthia found out about his affair with Yoko Ono.
McCartney specifically went to see five-year-old Julian because he had become almost an uncle to the youngster.
While travelling, Paul, came up with Hey Jules, a song intended to comfort a little boy caught up in a very public marital breakdown.
The song later mutated into Hey Jude because it was easier to sing.
Mr Goldman said: "What is special about this exhibition is not the artefacts themselves, although they are undoubtedly significant, it is the emotive impact.
"Seeing Paul's handwritten notes for Hey Jude and then hearing Cynthia and Julian explaining how important they are to them leaves you almost in tears."
The exhibition is a world premiere and the first chance for The Beatles Story to try out its new space at the Pier Head Ferry Terminal.
Curator Ann Darby said: "Having this brand new area, about 3,000 sq ft, has allowed us to produce the largest exhibition we have ever managed.
"The audio visual aspect is very important and you can see the emotion on their faces as they talk.
"What is interesting is John always heard it as a song for him.
"He thought subconsciously Paul was saying, go ahead, leave, giving his blessing."
Other Lennon chattels on show include his Afghan coat, the cape he wore in Help! and four guitars, including one with an inscription given to Julian in Christmas 1973.
The show will open at the Pier Head arm of The Beatles Story, on June 17.
BILLY MCCUTCHEON, HAMILTON, SCOTLAND around 8 months, 1 week ago