Today, some 80 years later, Walt Disney’s Fantasia (1940) is still regarded as a cinematic masterpiece for its breathtaking animation. But the film was historic in other ways, as well, being the first film to be released with a four-channel soundtrack.

In the days long before multi-tracking, Leopold Stokowski and the Philadelphia Orchestra’s performances were recorded onto nine separate synchronized optical 35mm film recorders using a collaborative Disney Productions/Bell Labs/RCA technology later referred to as “Fantasound.” The tracks were then mixed to four optical channels for theatrical release using newly developed “panpots” that would feed left, center, and right speakers behind the screen and 65 small speakers surrounding the audience.

The film was released in 1940 to critical acclaim at the Broadway Theater in New York City. Due to the costs/complexity of the playback system (and the outbreak of World War II), Fantasia was only shown in this format in a dozen other cities. It was later reissued as a mono version in 1940 and was revived as a stereo release with magnetic sound-on-film soundtrack in 1956, the eventual precursor to today’s Dolby stereo film formats.