Music played with instruments seen in most orchestras and concert bands is acoustic. Acoustic, when applied to music, means that it is produced by an instrument or instruments that do not rely on electronics for their sound production. Electronic, when applied to music, means that it is produced and/or altered by electronic means. Electronic music can, therefore, refer to several different types of music, including acoustic music that has been altered electronically, as well as different kinds of music that are produced using a variety of electronic means. For the child who plays sometimes on a MIDI keyboard that sounds like an acoustic piano and sometimes on an actual acoustic piano, the distinction probably doesn’t loom as large as it did when electronic music was a new and radical idea.
Electronic music emerged due to ongoing efforts in laboratories in a number of countries in the northern hemisphere from the 1890s to the 1950s. In its early days, electronic music referred only to a compilation of sounds synthesized electronically to distinguish it from musique concrete, which combined acoustic music with everyday sounds. Later the definition came to cover both and continued to broaden as new technology continued to develop. Some of the early and well-known composers of electronic music include Milton Babbitt, Pierre Boulez, John Cage, Krzystof Penderecki, Karlheinz Stockhausen, and Edgard Varèse.
The original equipment of electronic music included the dynamic suppressor, filter, ring modulator, sine-tone generator, square wave generator, variable speed tape recorders, and white sound generator. In the 1960s, synthesizers were introduced, and the one that American Robert A. Moog developed was particularly influential, providing additional sounds. The development of the sequencer, also in the 1960s, allowed the synthesizer to be programmed. With the advent of the personal computer, the synthesizer and sequencer went from being rare instruments in the hands of specialists to common and available resources.
Purists distinguish between electric and electronic music and instruments, reserving electronic only for instruments and music in which the sound is generated by electronic oscillators or digital circuitry, not merely amplified through electric means. Electronic instruments proper, and therefore those that make electronic music, include synthesizers and a variety of keyboards, electronic organs including the Hammond organ, and electronic percussion, as well as the ondes martenot and the theremin. The ondes martenot was developed by Frenchman Maurice Martenot and underwent considerable development in how it was controlled, but it always required two hands to control the pitch, articulation dynamics, timbre, etc. of the sound. The theremin was developed by Lev Theremin, a Russian, and is played by hand movements that do not touch the instrument. It was used in the Beach Boys’ song “Good Vibrations.”