Leonard Gregory Kastle (11 February 1929 – May 18, 2011) was an opera composer, librettist, and director, though he is best known as the writer/director of The Honeymoon Killers, his only venture into the cinema, for which he did all his own research. He was educated at the Curtis Institute of Music studying under opera composer Gian Carlo Menotti and also the Juilliard School. He was an adjunct member of the SUNY Albany music faculty.
His operas include Deseret (1961), on a libretto by Anne Howard Bailey about Brigham Young, which he directed for the NBC Opera Theatre. He wrote in a Romantic style that he believed the music academy did not hold in high regard as something for contemporary composers to do. His favorite composer was Gustav Mahler, whom he believed was not at all respected when he was in music school.
In 1956, Kastle composed a thirteen-minute "made-to-measure" opera, titled The Swing, for two singers, a speaking part, and piano accompaniment. It was commissioned by and broadcast on the NBC television network on Sunday, June 10, 1956, at noon. He also wrote The Pariahs, about the sinking of the whaling ship Essex, a trilogy of operas about the Shakers known under the collective title The Passion of Mother Ann: A Sacred Festival Play, a children's opera called Professor Lookalike and the Children, a piano concerto, sonatas for piano and violin, and three unproduced screenplays, Wedding at Cana, Change of Heart, and Shakespeare's Dog. In a 2003 interview for the Criterion Collection, he said that no producer wanted Wedding at Cana, just another Honeymoon Killers, which he did not want to do.
After The Honeymoon Killers, Kastle returned to teaching and composing. After the Criterion release of the film, he was rediscovered by a new generation of cult film enthusiasts and occasionally attended film-related events such as the Ed Wood Film Festival in 2007, where he served on the panel of judges
- Leonard Kastle Papers - Biographical Sketch from the University at Albany
- Grimes, William (May 21, 2011). "Leonard Kastle, Composer and Filmmaker, Dies at 82". New York Times
- Leonard Kastle interview, The Honeymoon Killers DVD, Criterion Collection
- E[dward] D[ownes], "13-Minute Opera Bows on TV Program", New York Times (June 12, 1956).
- EdWood update: Kastle keeps court THE MOVIEGOER by Casey Seiler, entertainment editor for TimesUnion.Com September 14, 2007
- Leonard Kastle at the Internet Movie Database
- The Leonard Kastle Papers from the University at Albany
- Leonard Kastles Obituary & Condolence Book