AI was used to bring the song together

Ringo and Paul used the same technology to isolate and improve Lennon's vocal that was employed to enhance the audio in Peter Jackson’s documentary series 'The Beatles: Get Back'.

In new documentary 'Now And Then - The Last Beatles Song', Paul recalled: "They said this is the sound of John's voice [imitates computer noise].

"A few seconds later and there it was, John's voice, crystal clear. It was quite emotional."