This movie was based on the life of conductor Daniel Barenboim and his wife, cellist Jacqueline du Pré, whose life was examined in Hilary and Jackie (1998).
The original 1980 East End production of "Duet for One" on stage at the Bush Theatre in Shepherd's Bush in London, England featured Frances de la Tour and David de Keyser in the lead roles of Stephanie Anderson and David Cornwallis, who represented the real-life married personages of cellist Jacqueline du Pré and conductor Daniel Barenboim, respectively. The play was such a success that it transferred to The Duke of York's theatre in the West End.
The movie's source 1980 stage play of the same name by playwright Tom Kempinski is a "two-hander", which means it features an entire cast of just two performers, in this case just the one actor and just the one actress.
Reportedly, this movie is only minimally fictionalized from its source material about the lives of cellist Jacqueline du Pré and conductor Daniel Barenboim, which mainly includes its source 1980 stage play of the same name by Tom Kempinski.
The Broadway stage production of the film's source ''Duet for One'' stage play by Tom Kempinski opened at the Royale Theatre on 17th December 1981 where it played for twenty performances before it closed on 2nd January 1982. This stage production was directed by William Friedkin and starred Anne Bancroft as Stephanie Abrahams and Max Von Sydow as Dr. Alfred Feldman.