This movie is loosely based on the true story of Soeur Sourire, who had a #1 pop hit in America with "Dominique" in 1963. Unfortunately, the nun was a one-hit wonder whose life did not continue happily after her chart success. After leaving the church for a full-time music career, she ran into heavy financial problems and eventually took her own life in Belgium in 1985.
Debbie Reynolds and director Henry Koster had a poor working relationship on this film, which led Koster, at age 60, to retire from film-making. Reynolds went as far as to tell a British TV interviewer a few years later that Koster had "gone senile" during the filming, which was untrue.
Debbie Reynolds did an excellent job portraying guitar accompaniment. In virtually every case where her hands were shown, her chord fingering and right-hand playing were accurately matching the guitar chords/notes as heard, indicating that she was at least accomplished at a basic level.