An electronic musical instrument or electrophone is a musical instrument that produces sound using electronic circuitry. Such an instrument sounds by outputting an electrical, electronic or digital audio signal that ultimately is plugged into a power amplifier which drives a loudspeaker, creating the sound heard by the performer and listener.
An electronic instrument may include a user interface for controlling its sound, often by adjusting the pitch, frequency, or duration of each note. A common user interface is the musical keyboard, which functions similarly to the keyboard on an acoustic piano where the keys are each linked mechanically to swinging string hammers - whereas with an electronic keyboard, the keyboard interface is linked to a synth module, computer or other electronic or digital sound generator, which then creates a sound. However, it is increasingly common to separate user interface and sound-generating functions into a music controller (input device) and a music synthesizer, respectively, with the two devices communicating through a musical performance description language such as MIDI or Open Sound Control. The solid state nature of electronic keyboards also offers differing feel and response, offering a novel experience in playing relative to operating a mechanically linked piano keyboard.
All electronic musical instruments can be viewed as a subset of audio signal processing applications. Simple electronic musical instruments are sometimes called sound effects; the border between sound effects and actual musical instruments is often unclear.
In the 21st century, electronic musical instruments are widely used in most styles of music. In popular music styles such as electronic dance music, almost all of the instrument sounds used in recordings are electronic instruments (e.g., bass synth, synthesizer, drum machine). Development of new electronic musical instruments, controllers, and synthesizers continues to be a highly active and interdisciplinary field of research. Specialized conferences, such as the International Conference on New Interfaces for Musical Expression, have organized to report cutting-edge work, as well as to provide a showcase for artists who perform or create music with new electronic music instruments, controllers, and synthesizers.
Classification In musicology, electronic musical instruments are known as electrophones. Electrophones are the fifth category of musical instrument under the Hornbostel-Sachs system. Musicologists typically only classify music as electrophones if the sound is initially produced by electricity, excluding electronically controlled acoustic instruments such as pipe organs and amplified instruments such as electric guitars.
The category was added to the Hornbostel-Sachs musical instrument classification system by Sachs in 1940, in his 1940 book The History of Musical Instruments; the original 1914 version of the system did not include it. Sachs divided electrophones into three subcategories:
51=electrically actuated acoustic instruments (e.g., pipe organ with electro-pneumatic or direct electric action) 52=electrically amplified acoustic instruments (e.g., acoustic guitar with pickup) 53=instruments which make sound primarily by way of electrically driven oscillators
The last category included instruments such as theremins or synthesizers, which he called radioelectric instruments.
Francis William Galpin provided such a group in his own classification system, which is closer to Mahillon than Sachs-Hornbostel. For example, in Galpin's 1937 book A Textbook of European Musical Instruments, he lists electrophones with three second-level divisions for sound generation ("by oscillation", "electro-magnetic", and "electro-static"), as well as third-level and fourth-level categories based on the control method.
Present-day ethnomusicologists, such as Margaret Kartomi and Terry Ellingson, suggest that, in keeping with the spirit of the original Hornbostel Sachs classification scheme, if one categorizes instruments by what first produces the initial sound in the instrument, that only subcategory 53 should remain in the electrophones category. Thus, it has been more recently proposed, for example, that the pipe organ (even if it uses electric key action to control solenoid valves) remain in the aerophones category, and that the electric guitar remain in the chordophones category, and so on.
Early examples
In the 18th-century, musicians and composers adapted a number of acoustic instruments to exploit the novelty of electricity. Thus, in the broadest sense, the first electrified musical instrument was the Denis d'or keyboard, dating from 1753, followed shortly by the clavecin électrique by the Frenchman Jean-Baptiste de Laborde in 1761. The Denis d'or consisted of a keyboard instrument of over 700 strings, electrified temporarily to enhance sonic qualities. The clavecin électrique was a keyboard instrument with plectra (picks) activated electrically. However, neither instrument used electricity as a sound source.
The first electric synthesizer was invented in 1876 by Elisha Gray. The "Musical Telegraph" was a chance by-product of his telephone technology when Gray discovered that he could control sound from a self-vibrating electromagnetic circuit and so invented a basic oscillator. The Musical Telegraph used steel reeds oscillated by electromagnets and transmitted over a telephone line. Gray also built a simple loudspeaker device into later models, which consisted of a diaphragm vibrating in a magnetic field.
A significant invention, which later had a profound effect on electronic music, was the audion in 1906. This was the first thermionic valve, or vacuum tube and which led to the generation and amplification of electrical signals, radio broadcasting, and electronic computation, among other things. Other early synthesizers included the Telharmonium (1897), the Theremin (1919), Jörg Mager's Spharophon (1924) and Partiturophone, Taubmann's similar Electronde (1933), Maurice Martenot's ondes Martenot ("Martenot waves", 1928), Trautwein's Trautonium (1930). The Mellertion (1933) used a non-standard scale, Bertrand's Dynaphone could produce octaves and perfect fifths, while the Emicon was an American, keyboard-controlled instrument constructed in 1930 and the German Hellertion combined four instruments to produce chords. Three Russian instruments also appeared, Oubouhof's Croix Sonore (1934), Ivor Darreg's microtonal 'Electronic Keyboard Oboe' (1937) and the ANS synthesizer, constructed by the Russian scientist Evgeny Murzin from 1937 to 1958. Only two models of this latter were built, and the only surviving example is currently stored at the Lomonosov University in Moscow. It has been used in many Russian movies—like Solaris—to produce unusual, "cosmic" sounds.All the preceding instruments except those of Darreg and Murzin described in P. Scholes, The Oxford Companion to Music, 10th Ed. OUP, p.322
Hugh Le Caine, John Hanert, Raymond Scott, composer Percy Grainger (with Burnett Cross), and others built a variety of automated electronic-music controllers during the late 1940s and 1950s. In 1959 Daphne Oram produced a novel method of synthesis, her Oramics technique, driven by drawings on a 35 mm film strip; it was used for a number of years at the BBC Radiophonic Workshop. This workshop was also responsible for the theme to the TV series Doctor Who a piece, largely created by Delia Derbyshire, that more than any other ensured the popularity of electronic music in the UK.
Telharmonium
In 1897 Thaddeus Cahill patented an instrument called the Telharmonium (or Teleharmonium, also known as the Dynamaphone). Using tonewheels to generate musical sounds as electrical signals by additive synthesis, it was capable of producing any combination of notes and overtones, at any dynamic level. This technology was later used to design the Hammond organ. Between 1901 and 1910 Cahill had three progressively larger and more complex versions made, the first weighing seven tons, the last in excess of 200 tons. Portability was managed only by rail and with the use of thirty boxcars. By 1912, public interest had waned, and Cahill's enterprise was bankrupt.
Theremin
Another development, which aroused the interest of many composers, occurred in 1919–1920. In Leningrad, Leon Theremin built and demonstrated his Etherophone, which was later renamed the Theremin. This led to the first compositions for electronic instruments, as opposed to noisemakers and re-purposed machines. The Theremin was notable for being the first musical instrument played without touching it. In 1929, Joseph Schillinger composed First Airphonic Suite for Theremin and Orchestra, premièred with the Cleveland Orchestra with Leon Theremin as soloist. The next year Henry Cowell commissioned Theremin to create the first electronic rhythm machine, called the Rhythmicon. Cowell wrote some compositions for it, which he and Schillinger premiered in 1932.
Ondes Martenot
The ondes Martenot is played with a keyboard or by moving a ring along a wire, creating wavering sounds similar to a theremin. It was invented in 1928 by the French cellist Maurice Martenot, who was inspired by the accidental overlaps of tones between military radio oscillators, and wanted to create an instrument with the expressiveness of the cello.Jean Laurendeau: Maurice Martenot: Luthier de l'Electronique (Dervy Livres, 1996)
The French composer Olivier Messiaen used the ondes Martenot in pieces such as his 1949 symphony Turangalîla-Symphonie, and his sister-in-law Jeanne Loriod was a celebrated player. It appears in numerous film and television soundtracks, particularly science fiction and horror films. Contemporary users of the ondes Martenot include Tom Waits, Daft Punk and the Radiohead guitarist Jonny Greenwood.
Trautonium
The Trautonium was invented in 1928. It was based on the subharmonic scale, and the resulting sounds were frequently used to emulate bell or gong sounds, as in the 1950s Bayreuth productions of Parsifal. In 1942, Richard Strauss used it for the bell- and gong-part in the Dresden première of his Japanese Festival Music. This new class of instruments, microtonal by nature, was only adopted slowly by composers at first, but by the early 1930s there was a burst of new works incorporating these and other electronic instruments.
Hammond organ and Novachord
In 1929 Laurens Hammond established his company for the manufacture of electronic instruments. He went on to produce the Hammond organ, which was based on the principles of the Telharmonium, along with other developments, including early reverberation units.Russcol 1972, 70. The Hammond organ is an electromechanical instrument, as it used both mechanical elements and electronic parts. A Hammond organ used spinning metal tonewheels to produce different sounds. A magnetic pickup similar in design to the pickups in an electric guitar is used to transmit the pitches in the tonewheels to an amplifier and speaker enclosure. While the Hammond organ was designed to be a lower-cost alternative to a pipe organ for church music, musicians soon discovered that the Hammond was an excellent instrument for blues and jazz; indeed, an entire genre of music developed built around this instrument, known as the organ trio (typically Hammond organ, drums, and a third instrument, either saxophone or guitar).
The first commercially manufactured synthesizer was the Novachord, built by the Hammond Organ Company from 1938 to 1942, which offered 72-note polyphony using 12 oscillators driving monostable-based divide-down circuits, basic envelope control and resonant low-pass filters. The instrument featured 163 vacuum tubes and weighed 500 pounds. The instrument's use of envelope control is significant, as it is perhaps the most distinguishing feature of the modern synthesizer compared to other electronic instruments.