III.

Synthesizers and Other Electronic Technology

In the 1950s sound synthesizers were developed, principally in the United States. Synthesizers enabled composers to produce sounds electronically in almost any range, tone quality, and volume by feeding information about the structure of the sound into a computer. At first composers using synthesizers concentrated on imitating instrumental sounds but in time they began to experiment with producing new sounds. They could create entirely new sounds by layering or mixing many tones in a process called additive synthesis, or they could filter sound by means of subtractive synthesis.

One of the earliest electronic synthesizers was a room-sized RCA computer at the Columbia-Princeton Electronic Music Center. American mathematician and composer Milton Babbitt used it to compose music based on serial principles similar to those of Eimert and Stockhausen in Cologne. Babbitt’s work Philomel (1964) was one of the first to be written for live performer (soprano) and synthesized sounds on tape. The development of computing technology in the 1950s and 1960s led to the establishment of studios specifically concerned with computer music at a number of American universities.

By the mid-1960s American engineers Robert Moog and Donald Buchla had assembled electronic devices to produce what they called modular musical synthesizers. These synthesizers used semiconductor technology rather than vacuum tubes, and they could be controlled by piano-style keyboards or by pressure-sensitive pads. In addition, they could store sounds and reproduce them later. American composer Morton Subotnick used a Buchla synthesizer to create Silver Apples of the Moon (1967), one of the early and influential electronic compositions. By the late 1960s Moog had introduced a smaller, less expensive version of his synthesizer. Over time the number of possible synthesizer keyboards steadily increased, facilitating the production of ever greater and more complex sounds. Synthesizer memory also increased. During the late 1970s and the 1980s synthesizers began to incorporate personal computer technology. Recorded sound samples could then be edited and transformed. The availability of relatively inexpensive synthesizers helped electronic music gain popularity.

Synthesizers that offered a range of preset sounds and effects were used increasingly for commercial purposes, from advertising jingles on television to motion-picture soundtracks. Pink Floyd and other popular music groups also began to use synthesizers during the late 1960s. Moog developed a modernized version of the theremin using transistors; it produces the wailing sounds in the chorus of The Beach Boys’ 1966 hit “Good Vibrations.” But it was composer Wendy (then Walter) Carlos who demonstrated what the synthesizer could do by using one to render fugues and inventions by German composer Johann Sebastian Bach for the album Switched on Bach (1969).

In 1982 synthesizer technology and the creation of electronic music were advanced by the development of MIDI (Musical Instrument Digital Interface). MIDI is a means of enabling synthesizers to communicate with one another during performance by sending digital instructions. Using MIDI a performer can, for example, arrange for several different synthesizers to respond when a keyboard linked to one synthesizer is played. Computing technology also enabled the invention of the keyboard sampler, an electronic instrument that digitally records small bits, or samples, of sound and then plays them back.

From the 1980s on advances in computer technology also facilitated live electronic performances in which the music is generated or transformed during the performance rather than recorded beforehand. Dutch composer Michel Waisvisz, for example, performs with The Hands, an instrument developed in the mid-1980s that uses sensors and physical touch to generate music. The movement of his hands in space triggers complex sounds and sonic manipulations. American composer and trombonist George Lewis combines trombone improvisation with customized computer composition programs that improvise during the performance. French performance artist Laetitia Sonami controls computer-processed sounds onstage with The Lady’s Glove, an instrument developed in the 1990s that is sensitive to pressure and motion. By the 1990s computers were even able to improvise during performances, using rules developed in advance by the composer.