Morning Edition, February 7, 2005 · The 1956 sci-fi thriller Forbidden Planet was the first major motion picture to feature an all-electronic film score -- a soundtrack that predated synthesizers and samplers. It was like nothing the audience had seen -- or heard. The composers were two little-known and little-appreciated pioneers in the field of electronic music, Louis and Bebe Barron.
Married in 1947, the Barrons received a tape recorder as a wedding gift. They used it to record friends and parties, and later opened one of the first private sound studios in America. The 1948 book Cybernetics: Or, Control and Communication in the Animal and the Machine, by MIT mathematician Norbert Wiener, inspired Louis Barron to build electronic circuits, which he manipulated to generate sounds. Bebe's job was to sort through hours and hours of tape. Together they manipulated the sounds to create an otherworldly auditory experience.
The Barrons' music caught the ear of the avant-garde scene: In the early 1950s, they worked on a year-long project with composer John Cage. They also scored several short experimental films.
But avant-garde didn't pay, and the Barrons decided to cash in by turning to Hollywood. Their score for Forbidden Planet drew critical praise, but a dispute with the American Federation of Musicians prevented them from receiving proper credit for the soundtrack. Their names were also left off the film's Oscar nomination.
Union rules continued to be an obstacle, and technology eventually passed the Barrons by. Though they never scored another film, Louis and Bebe Barron, who divorced in 1970, continued to collaborate until his death in 1989.
source + soundexcerpts
Thanks to Mark R. from soundasart mailing group for pointing this out.