Question: What unreleased song's tune was re-used in a song which appeared on the 1971 album 'Imagine' by John Lennon?
Sentence (from "Jealous Guy"): It is one of the most commonly recorded Lennon songs, with at least 92 other recorded versions, the most notable being Roxy Music's version, which reached number one in several countries three months after John Lennon's death.
Relevant evidence: No