Simple but impressive magic trick.
"Now and Then" is a psychedelic soft rock ballad that John Lennon wrote and recorded in around 1977 as a five-minute solo piano home demo, but left unfinished. After Lennon's death in 1980, the song was considered as the third Beatles reunion single for their 1995–1996 retrospective project The Beatles Anthology, following "Free as a Bird" and "Real Love", both based on Lennon's demos. Instead, it was shelved for nearly three decades, until it was completed by the surviving bandmates Paul McCartney and Ringo Starr, using overdubs and guitar tracks by George Harrison (who died in 2001) from the abandoned 1995 sessions. The final version features additional lyrics by McCartney, and Lennon's voice extracted from the demo using the AI-backed audio restoration technology commissioned by Peter Jackson for his 2021 documentary The Beatles: Get Back.