The Masterpiece Behind the Music in A Clockwork Orange

It was the first film to use Dolby A, a noise-reduction sound system developed by IEEE Life Fellow Ray Dolby

8 December 2016

Forty-five years ago this month the dystopian crime film A Clockwork Orange premiered in New York City and with it the first soundtrack to be recorded with a groundbreaking new sound system: the Dolby A. The system had been invented in 1965 by IEEE Life Fellow Ray Dolby [above].

On 9 January 1972, The New York Times led its Arts and Leisure section with a long review of the controversial movie, directed by renowned filmmaker Stanley Kubrick and based on a novel by Anthony Burgess. The movie had just won the 1971 New York Film Critics’ Award for best film, despite its portrayal of nihilistic violence and sex, which earned it an X rating.

The reviewer, leading critic Vincent Canby, called it a work of genius. One of the artistic features that he highlighted was the brilliant use of the soundtrack to complement the visual effects. Initially, however, the soundtrack hardly made waves.

It drew more attention when the soundtrack’s composer, Walter Carlos (Wendy Carlos today), released a second version of the soundtrack in February 1972 that included new musical elements. Music critic Don Heckman’s review in the Times drew attention to the album with its “recomposition” (as he termed it) of classical, American standard, and original music. Heckman declared it to be “a work of genius” and only mentioned in passing Carlos’s use of a Moog synthesizer, which was developed by IEEE Life Member Robert Moog. What both the film and music critics missed was another work of genius: Dolby sound.


In 1965, American electrical engineer Ray Dolby returned to the United Kingdom from India, where he served as a technical advisor for the United Nations. Dolby’s focus was on audio engineering, and he had an idea for a new kind of noise-reduction system for magnetic tape recordings, then the system of choice for recording audio. He founded a company in London, Dolby Laboratories, and developed Dolby A, a sound system for professional recording studios.

At the time, a signal recorded on magnetic tape had a hissing noise in the background composed mainly of higher frequencies. Dolby set out to eliminate the hiss by pre-emphasizing the desired high frequencies before they are recorded so as to make them greater than the hissing noise with which they competed. When recorded music is loud, the hissing is not as noticeable, but when the music is soft or there is silence, most of what is heard is the hissing. If the recording level is adjusted so that the music is always recorded loud, then it could be turned down later, and the noise volume would also be turned down.

Dolby A was modestly successful, and in 1967, Dolby moved his company to San Francisco to join the emerging scene of what would become Silicon Valley.

The following year, Dolby introduced a version of his system for the home—Dolby B—a noise-reduction system primarily for playing cassette tapes. It was much simpler than Dolby A and inexpensive enough to implement in consumer products such as portable and car cassette players. And it was a huge success.

On 15 March 1970, in a review for the Times, Donal Henahan made an observation about technology and Dolby B that was rare for a music critic: “There is no such thing as a revolution; there are only innumerable small changes that go on while our backs are turned. To observers who have kept tuned to tape-recording technology in recent years, nothing could be less surprising than the emergence of the cassette as a high-fidelity medium.” Henahan credited Dolby B as the final small change that put the audio system over the top for sound recording.

As a pioneer of electronic music, Carlos was one of the early adopters of Dolby A for recording and mixing sound, and saw the potential for consumers having a parallel technology for playback. Dolby technology began to take off.


One area that remained unaffected by the new recording technology was the audio tracks for films. Dolby had long said that movie soundtracks were a medium where noise reduction could have a huge impact, but Hollywood was conservative when it came to new technology. The break came when Kubrick hired Carlos to write the score for Clockwork. Carlos and producer Rachel Elkind contacted Ioan Allen of Dolby Laboratories and arranged a meeting with Kubrick. They sold Kubrick on the idea of being the guinea pig for the use of Dolby technology in film.

It was a tremendous success, even if many of the critics and general public were unaware why their auditory experience was so striking. They were listening to the first high-fidelity sound on a film.

Like the gears inside a mechanical clock, the technological infrastructure that makes many things possible often goes unobserved. But the film industry noticed the Clockwork soundtrack, and the use of Dolby technology grew until it became the standard. To date Dolby Laboratories has won a dozen technical Academy Awards.

Ray Dolby and Dolby Laboratories went on to have a long string of successes. Dolby technology is incorporated into DVD and many HDTV standards. Ray Dolby, who received the 2010 IEEE Edison Medal among many other recognitions, died in 2013. His company is still going strong, and his legacy lives on.

Michael Geselowitz is senior director of the IEEE History Center, which is partially funded by donations to the IEEE Foundation.

This article has been updated. 

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