Elton worked extensively with Lennon on his 1974 ‘Walls and Bridges’ album, providing backing vocals and piano on the lead single ‘Whatever Gets You Through The Night’.
Despite not being a firm favourite of Lennon’s, Elton convinced him to release the track – and wagered that they would have to perform the number together if it topped the Billboard Hot 100.
When the song went on to bag the top spot and became a massive hit, Elton revealed that Lennon was then faced with battling his nerves before the pair performed it in November 1974.
Opening up to Sean Ono Lennon for the BBC Radio 2 series John Lennon at 80, Elton explained that Lennon had not played solo since the Toronto Rock and Roll Revival festival in 1969.
“He was terrified,” Elton told Sean. “I can tell you that he was physically sick before the show, absolutely physically sick.”
Describing the eventual performance, Elton recalled: “When he came on stage he was fine because the reception that he got at Thanksgiving Madison Square Garden in 1974… I’ve never heard a noise, a roar like it and… we all get goosebumps thinking about it.”
Elton recollected: “A lot of us cried and there were tears running down our faces because here was one of the four people that were [in] the biggest band ever.”
He went on to explain that Lennon “wasn’t nervous during the show [and] he just played the same brilliantly” once he arrived on stage.
They are believed to have reconciled before John was shot dead by Mark Chapman in New York in December 1980.
It was recently confirmed that Lennon’s glasses and a detention sheet from when the late Beatle was in school have gone up for auction, marking 50 years since their split.