In 1971, the year after The Beatles broke up, Lennon and Ono moved from London to New York, where they lived in a small Greenwich Village apartment for 18 months. A new film documents that period.

The concerts were the only full-length performances Lennon gave after the 1970 breakup of The Beatles. John and Yoko were backed by the New York City-based rock band Elephant’s Memory and famed ...