The Beatles just released a short film about how the upcoming single "Now and Then" has come about.
John Lennon had created a cassette demo of the song, and when the other three Beatles made their Anthology albums in 1995, they tried to use the cassette to play around his voice and make a new song. George Harrison played some guitar in that effort, but it was decided that the quality of John's vocals on the cassette were muddied by the piano playing, and they were unusable. The song was abandoned.
Now, with Peter Jackson's new audio separation technology, developed for their documentary "Get Back," it's become possible to separate John's voice from the piano and improve its quality. Combined with the guitar work George laid down in 1995, Paul McCartney and Ringo Starr could add their parts and produce a brand new Beatles single: written by John, with guitar by George, bass by Paul and drums by Ringo.
It's a beautiful song, especially in the context of John and George's death, and perfectly appropriate as a coda to the incredible catalog of Beatles music.
I've heard the full, final single, and I was initially concerned that it would sound like inauthentic music that's been forced and cobbled together to try to fake something that's long gone.
But it's not.
It's a Beatles song.