“Now and Then” will (allegedly) be the last song to feature all four Beatles. John’s vocals comes from a demo cassette that he recorded on a boombox in his Dakota apartment in 1978 (scroll down for that). George’s parts come from an abandoned attempt to record the song in 1994. Using modern AI tech, the song now lives.
Here’s the documentary on how it all came together.
And here’s the source material (via Oreo) for John’s parts. Beware that it might disappear from the internet any second.