In the history of electronic music, Canadian physicist Hugh Le Caine (1914-77) stands out as an important and somewhat enigmatic figure. A pioneer in

In the history of electronic music, Canadian physicist Hugh Le Caine (1914-77) stands out as an important and somewhat enigmatic figure. A pioneer in radar technology during World War II, and later in microwave transmission and atomic physics, Le Caine used his scientific knowledge to create tools that would give musicians and composers remarkable control over sound production.

His instruments, which included multitrack tape machines and touch-sensitive keyboards, explored important concepts such as voltage control years before that technology entered mainstream electronic music. Le Caine's inventions eventually populated many early electronic-music studios developed in the '50s and '60s. However, none of his inventions went into commercial production, and until recently, little was known about the inventor, who shunned the limelight to concentrate on research and development.

Le Caine began building musical instruments and experimenting with electronic devices in his youth. He imagined that beautiful sounds could be realized through new electronic inventions. Although he played his instruments, he didn't consider himself to be a musician or composer. Consequently, he left few recorded examples of his work. His 1955 composition Dripsody is a tape-music masterpiece and his best known work. His other recordings, compiled on the CD Hugh Le Caine: Compositions, Demonstrations 1946-1974, include additional compositions as well as instrument demonstrations and private recordings made on an acetate disc recorder.

Le Caine earned his master of science in engineering physics in 1939 from Queen's University in Kingston, Ontario, and joined the National Research Council of Canada (NRC) in Ottawa. He was an ace problem solver who could correct any faulty circuit.

Le Caine began designing electronic musical instruments in his home studio. In 1954, on the strength of his public lectures and demonstrations, he was permitted to work full-time developing new instruments. He created 22 instruments during the next 20 years, and his NRC lab equipped, almost single-handedly, the electronic-music studios at the University of Toronto (opened in 1959) and McGill University in Montreal (opened in 1964).


In the late '40s, Le Caine used voltage-control techniques to vary a sound's harmonic spectrum independently of frequency and intensity. Although the voltage-controlled oscillator (VCO) was already a well-known device, the use of continuously variable voltages to model sound waves was a new approach that anticipated the use of voltage control in analog synthesizers of the '60s.

As early as the summer of 1937, while he was still a student, Le Caine linked his work in atomic physics to his ideas about electronic music: his Free Reed Organ used circuits that were known only to those involved in radio and scientific research. He and his colleagues used those circuits daily, but not within the audio range. It was Le Caine's inspiration to transpose them into the realm of sound and explore the musical characteristics of waveshapes that led to the instrument's development.

The Free Reed Organ consisted of a second-hand organ with two ranks of reeds that were blown constantly at low pressure by a vacuum cleaner. The resulting vibrations were picked up electrostatically, because the keys applied a voltage to the vibrating reeds so that they acted as variable condensers. Le Caine also designed a variable attack for the instrument, which anticipated his later touch-sensitive keyboards. Le Caine considered the Free Reed Organ to be his first successful instrument. It was still played ten years later, though no known recordings of it exist.

Le Caine built the instrument partly to test the accuracy of the reed frequencies' electrostatic translation, and he found that the method provided good frequency stability. The design had immediate lab applications. Atomic physics is highly dependent on electronics, and that summer, Le Caine designed an innovative and highly accurate device for measuring tiny electrical charges, the first vibrating reed electrometer. The device worked on the same principle as the condenser microphone, which translates physical movement into an electrical current.

Physical proximity is the basis of that technology, which remained characteristic of Le Caine's designs for many years. One adaptation employed film, graded gradually from light to dark, to control current transfer as the film moved back and forth in front of light sensors. Le Caine preferred to use real-time physical controllers whenever possible, and many of his innovations anticipated today's live-performance interfaces.


Le Caine thought about a monophonic electronic performance instrument for some time before he began work on the Sackbut (see Fig. 1). “The monophonic instrument is … the starting point of all musical thinking, and the polyphonic instrument is simply an expedient,” he said. For Le Caine, polyphonic instruments possessed little inherent musical value; they were merely more efficient, enabling one person to play the parts of several monophonic instruments.

He was not interested in redefining music but rather in providing an improved instrument for playing pop standards and classical music. Le Caine believed that musicians needed more control of pitch, volume, and tone quality to avoid the mechanical sound so familiar in electronic organs. He speculated that in spite of the electronic technology's flexibility, instrument designers tended to take control from the player to make their instruments easier to play. But he believed that such instruments merely became easier to play poorly, and that with an inadequate range of musical devices, it became more difficult to play music that would hold a listener's interest.

Le Caine addressed the limitations of conventional keyboards by giving Sackbut performers simultaneous control of pitch, volume, and timbre. At the keyboard, the right hand controlled pitch and volume; the left hand controlled the timbral elements — basic waveform, main formant, and auxiliary formant — using continuously variable voltages (see Fig. 2). Timbral vibrato, in which the waveform alternates between two settings, was possible with the waveform controller (see Fig. 3).

The Sackbut's expanded pitch and volume control depended on Le Caine-designed force-sensitive capacitors, which responded to the physical movement of the keys. The keyboard was mounted on springs so that each key could be moved vertically and horizontally by the performer. Moving a key sideways varied the current to the pitch controller. Similarly, vertical pressure was translated into volume adjustments.

The timbre controls of the Sackbut were crucial in establishing the instrument's musical sound. Le Caine understood that timbre changes constantly in acoustic instruments and that that characteristic cannot be replicated by an organ stop or other switching system. His initial experiments supported his speculation that continuous, detailed control of the waveform was essential in a musical instrument. Unlike pitch and volume, timbre is multidimensional; no matter how complex the pitch and volume controls might be, timbral variability was needed to produce a musically useful sound.

The electrostatic coupling device operated nearly all the Sackbut controls as it did in the Free Reed Organ's keyboard in 1937. In both instruments, a simple connection was made between two electrodes: the current transferred between them increased as they were brought closer together. That was the basis of the Sackbut's advanced timbre controls and its touch-sensitive keyboard, and it was a central feature in many of Le Caine's later models.


With the Sackbut, Le Caine succeeded in demonstrating the musical possibilities of both touch-sensitive keys and continuous timbre controls. But he also forged a link between music's subjective, expressive, and intuitive aspects and its physical basis in acoustics and electronics. His research integrated the arts with science and technology.

Le Caine's experiments revealed that people with little formal musical education played the Sackbut best. He concluded that that was because few musicians had a detailed awareness of sound's acoustical properties. “No one of any musical pretension, at least no practicing musician, ever paid any attention to the ‘physics of music,’” Le Caine said.

Few scientists had imagined that waveform generators, amplifiers, and frequency controllers could produce interesting musical sounds. To them, the worlds of science and music were separate. By bringing those worlds together in the Sackbut, Le Caine was leading anyone who played the instrument into unfamiliar territory.

To play the Sackbut, a musician had to think about a sound differently. Understanding the circuitry wasn't important, but understanding the nature of sound in acoustic terms — understanding the musical impact of noise, formant frequency, and wave shape — was essential. The Sackbut pointed toward the idea of electronic-music studios, in which composers could build sound waves from scratch.


From 1948 to 1952, Le Caine earned his Ph.D. in atomic physics at Birmingham University in England. He was awarded an NRC doctoral scholarship to compensate for his education having been cut short by World War II and in recognition of his wartime achievements.

His studies kept him away from his music lab for more than three years. While in England, he heard the BBC broadcast exciting music that was yet to be heard in North America. The field of electronic music was expanding throughout the industrialized world, and many techniques were being developed for recorded and electronically generated sound. Le Caine found musique concrète particularly fascinating.

Soon after he returned to Ottawa, Le Caine bought a tape recorder and spent hours exploring the possibilities of tape editing. The tape recorder made tape loops possible, which he found intriguing because the same sound could be repeated many times, something that never happened in nature.

Late in 1955, Le Caine completed Dripsody (an Etude for Variable Speed Recorder), his first composition using his multitrack playback equipment, the Multi-track Tape Recorder, or Multi-track (see Fig. 4). Le Caine made Dripsody entirely from the sound of one water droplet falling into a bucket. The piece, which is just 1 minute and 26 seconds long, is a classic because of the incredible musical results Le Caine achieved from such minimal resources.

Le Caine first recorded 30 minutes of individual water drops falling into a water-filled metal bucket. Next, he selected one example from the master tape and created a short tape loop. Using more than 1,000 prints of the original source loop and a mere 25 splices, Le Caine created several octaves of scales and arpeggios, which he assembled into the remarkable piece. He completed Dripsody in a single evening.

The first version of Dripsody was monophonic. By 1957, however, the Multi-track played six tapes simultaneously and included a mixer and stereo outputs (see Fig. 5). That inspired Le Caine to rework Dripsody in stereo. He also recorded a narrated demonstration of the steps taken in assembling the piece. During subsequent years, Le Caine created several short pieces and a few comic sketches using the Multi-track. Those pieces still display Le Caine's imagination and originality as well as his detailed awareness of the nature of sound.

The Multi-track's playback speed was controlled by a three-octave keyboard. Moving up an octave on the keyboard doubled the playback speed, and the sounds on the recording went up an octave. The keyboard on the later versions of the Multi-track was equipped with a glide strip, a conductive strip mounted behind the keyboard for playing wider glissandi than could be accomplished with horizontal key pressure.

Le Caine continually expanded the Multi-track's resources. By 1964 the instrument could play ten stereo tapes in two groups, and each group's speed could be controlled independently. The output could be fed to external devices such as Le Caine's Adjustable Filter, Two-Channel Alternator, and Envelope Shaper. In addition, speed changes of the Multi-track could be controlled automatically by the Serial Sound Structure Generator.


The Multi-track was not intended for private use but for use in a laboratory or studio. By the late '50s, electronic-music studios were opening at universities and radio stations around the world. In 1959 a studio featuring Le Caine's Multi-track opened at the University of Toronto. A few years later, Le Caine sent a Multi-track to a new studio at McGill University in Montreal. The Multi-track was the central instrument for both studios for many years. Le Caine built five models of the instrument, one of which was sent as a gift from the NRC to a university studio in Jerusalem, Israel.

Several U.S. studios inquired about buying a Multi-track, and the Electronics Associates of Toronto showed interest in manufacturing it. There was a plan to design a modular Multi-track so that a studio could buy a reduced version that would play two to four tapes simultaneously. The studio could add additional capacity and output features, such as mixers, later. But after several years, the design was not complete, and the project was abandoned.

After the Canadian university studios opened, Le Caine completed few compositions. He limited himself to demonstration recordings of new instruments, which he often played when he presented a paper or public lecture. He emphasized the design of equipment for use by those who had formal training as composers, and he designed instruments to facilitate their music. Between 1957 and 1959, for example, Le Caine created a bank of 108 oscillators (see Fig. 6), which he designed to work with the Spectrogram. The Spectrogram used 100 photocells to read a graphic score. As darkened sections of the score passed the photocells, the specified oscillators would sound (see Fig. 7).

In 1961 Le Caine created two smaller Oscillator Banks, with variable waveforms, operated by touch-sensitive keyboards (see Fig. 8). The final version of the Spectrogram controlled 25 separate output lines, each of which could be fed to an oscillator or to another device. It was used with the smaller oscillator banks, but the size of the graph paper makes clear that the Spectrogram originally had been designed for a larger number of generators.


Le Caine sent several modules, many of which were based on Sackbut components, to the studio in Toronto in 1962. The Level Control Amplifier was essentially a transistorized voltage-controlled amplifier (VCA) and had been used in the Multi-track. The Adjustable Filter had six inputs, each with separate controls for eight different bandwidths, for a total of 48 controllers. The six inputs indicate that the instrument was designed to integrate directly with the six outputs from the Multi-track so that composers could avoid creating extra tape generations in order to process source material. The Tone Shifter was a further development of the Sackbut's frequency modulator. It produced sidebands of great variety and expanded the degree of control by allowing for stepped or gliding changes of pitch.

In 1964 Le Caine sent another group of modules to the Toronto studio. The Function Generator combined a VCO with a staircase generator, which could also be used as a control voltage to shape an external signal. It also had adjustable settings to establish frequency and the timing of the changes. The Two-Channel Alternator could be set to automatically control stereo signals at various rates: the gain in one channel increased as the gain in the other was decreased, resulting in effects ranging from a choir effect to a slow pitch trill, tremolo or vibrato, or at higher rates, a buzz — even a sound resembling a ring modulator. Complex mixing and panning could be accomplished with the Two-Channel Alternator.

In 1965 Le Caine built the Envelope Shaper. Le Caine preferred to use manually operated touch-sensitive keys whenever possible, but the device provided a level of precision that could not be obtained manually. Also that year, the Tone Mixture Generator produced transposable clusters of sine waves. It consisted of 13 oscillators, each with pitch and amplitude controls.


From the mid-'60s onward, Le Caine's instruments became far more complex and powerful. The Serial Sound Structure Generator (1965-68) was an intricate device incorporating many of the smaller components that had been designed for the studio, including VCOs, amplifiers, filters, waveform generators, and automatic envelope controllers. The instrument used a serial switch similar to that used in early telephone switchboards. Separate modules stored sequences of pitches, durations, envelopes, and wave shapes. Each sequence could have 4 to 13 terms that could be played continuously, forward or backward.

The Serial Sound Structure Generator was a powerful device for serial and repetitive musical forms. In many ways, the device anticipated the simplified sequencers that began to appear on analog synthesizers at about the same time, although no analog sequencers approached the complexity of Le Caine's instrument. A working version of the instrument was installed at the Montreal World's Fair in 1967, where thousands of visitors set up their own sequences and heard them played.

The Sonde (1968) used only 30 oscillators to generate 200 sine waves (see Fig. 9). Combined with 20 regular oscillators were 10 converter-oscillators, which worked to suppress the 20 original frequencies and produced only the difference in tones of each regular oscillator. The system was tuned so that there was a 5 Hz difference between each of the 200 tones. The first version of the Sonde was built with 200 sliders. A later version, sometimes used for live performances, featured 200 printed-circuit touch-sensitive keys; the sound was activated by the conductivity of a player's finger, which completed the circuit printed on the keys.

The Polyphone (1970) was built for the studio at McGill University (see Fig. 10). That instrument had a three-octave polyphonic keyboard with touch-sensitive keys and several independently tunable oscillators and control voltages. The control panel allowed modules to be patched together. At floor level, the Polyphone had pressure-sensitive foot pedals that were operated using photosensitive controllers.

The Polyphone was built before polyphonic synthesizers were commercially available and presented powerful resources. Although it shared the unpredictability of many analog synthesizers, which weakened its usefulness as a performance instrument, a large number of tape compositions made at McGill used Polyphone-generated sounds.

In 1972 work began on the Paramus, one of the first hybrid music systems incorporating both analog and digital controls. It retained analog timbre controls and specially designed VCOs, but the timing and pitch controls were digital. It played four voices at one time. A digital oscillator was designed for the Paramus in 1973, but before the patent was processed, Le Caine retired, and the entire project closed.


Despite the decades of work Le Caine devoted to his inventions, their commercial potential was never fully realized. Working in a scientific research environment rather than with a musical-instrument manufacturer, he assumed that the inventions would be patented by the NRC and then made by a separate company. If he had worked directly with a manufacturing company, perhaps his instruments would have become readily available.

In 1954, when Le Caine began working full-time on musical instruments, he concentrated on his two instruments with the most commercial potential — the Sackbut and the Touch Sensitive Organ (see Fig. 11). The Touch Sensitive Organ had five electrostatic connectors attached to the bottom of each key. The keys were spring mounted to provide resistance to the performer. As the keys were pushed lower into the instrument's frame and the electrodes of the electrostatic connectors moved closer, the volume increased. The organ was presented at several trade shows and at lectures for the public and for scientific organizations.

Le Caine made detailed demonstration recordings of the advantages of touch sensitivity. In 1955 the Baldwin Organ Company took out the patent, apparently planning to bring out the touch-sensitive keyboard on a new electronic-organ model. The NRC's new music research lab succeeded in placing a patent quickly. Although Baldwin maintained the patent for several years, the company never manufactured the keyboard.

By 1969 there was a market for the Sackbut, and the instrument was redesigned using contemporary technologies (see Fig. 12). A manufacturer was awarded the contract to build the instrument, and it seemed that commercial success was just around the corner. The Polyphone and the Paramus would follow the Sackbut as more advanced models.

However, when the manufacturing company failed to produce an instrument after three years and subsequently refused to let another company take over, the project was abandoned. A general despondency settled over the entire project. NRC's administration made it known that it would not continue to support the lab after Le Caine's retirement, so he decided to leave immediately — he saw no reason to begin a new project under those circumstances.


In the end not one of Le Caine's instruments was manufactured commercially. When touch-sensitive keys became available in commercial electronic instruments in the early 1980s, they used a method different from his.

Le Caine's research team was awarded several patents and gave many presentations at conferences and at Audio Engineering Society meetings. Throughout the years, Le Caine gave public lectures and influenced a host of students who worked with his instruments at the university studios. Most people in the electronic-music field knew of Le Caine's work, but it is not known to what degree his instruments influenced other designers.

Perhaps the most important aspect of Le Caine's designs was their playability. His ideal was to enable nuance-filled, expressive performance, and touch sensitivity was an essential ingredient in that. Despite the technological hurdles he was forced to overcome, Le Caine was in fact able to add that ingredient to his keyboards, mixers, and other components, both mechanically and electronically.

Gayle Young is a composer and musician who works with electronic instruments. She is the author of a book about Hugh Le Caine, The Sackbut Blues, and the editor of Musicworks Magazine. For more information, visit


Hugh Le Caine: Compositions, Demonstrations 1946-1974 (JWD/EMF)

Anthology of Canadian Music: Electroacoustic Music (ACM)

University of Toronto Electronic Music Studio: Electronic Music (Folkways)