Electronic musical instrument

An electronic musical instrument is a musical instrument that produces its sounds using electricity. Sometimes the term electric instrument is used to mean instruments whose sound is produced mechanically, and only amplified electronically, such as an electric guitar. Either way, all electric and electronical musical instruments can be viewed as a subset of audio signal processing applications.

Early electronic musical instruments such as the Theremin and Ondes Martenot produced only pure tones and were mostly used to make avant garde music.

The most commonly used electronic instruments are synthesizers, so-called because they use the principles of substractive and additive synthesis to create sounds.

Synthesizers create sounds by direct manipulation of electrical currents which are then used to cause vibrations in the diaphragms of loudspeakers, headphones, etc. This synthesized sound is contrasted with recording of natural sound, where the mechanical energy of a sound wave is transformed into a signal which will then be converted back to mechanical energy on playback (though sampling significantly blurs this distinction).

The term "speech synthesizer" is also used in electronic speech processing, often in connection with vocoders.

Electronic musical instruments are now widely used in all styles of music.

Synthesizer basics

There two major kinds of synthesizers, analog and digital.

There are also many different kinds of synthesis methods, each applicable to both analog and digital synthesizers, but now most easily achieved with digital techniques.

Early electronic musical instruments

The earliest electronic musical instrument was the Theremin, invented by Leon Theremin in 1917, which used a vaccum tube oscillator to make sounds that depended on the interactions of the user with an RF field. This was followed in 1928 by the Ondes-Martenot which had a keyboard as well as several auxiliary controllers. The sound of the Ondes-Martenot is used extensively in the Turangalila Symphony by Olivier Messiaen. However, these were not true synthesizers in the modern sense, as they were not configurable to produce a range of complex sounds by additive or subtractive synthesis, instead generating single pure tones with controllable pitch, amplitude and vibrato.

The start of the analog synthesizer era

Early synthesizers used technology derived from electronic analog computers and laboratory test equipment.

In the 1950s, RCA produced experimental devices to synthesize both voice and music. The Mark II Music Synthesizer (1958) was only capable of producing music once it had been completely programmed; that is, the system had to be completely re-set for each new piece.

In 1958 Daphne Oram at the BBC Radiophonic Workshop produced a novel synthesizer using her "Oramics" technique, driven by drawings on a 35mm film strip. This was used for a number of years at the BBC.

In the mid-1960s, synthesizers were developed which could be played in real time but were confined to studios because of their size. A variety of signal processors were connected to a common controller.

The first widely used electronic musical instruments was the Moog synthesizer designed by Robert Moog, who set up a company to manufacture them. The first instruments were modular synthesizers, and Moog broke into the mass market with the Mini-moog an all-in-one instrument.

The first playable modern configurable music synthesizer was created by Robert Moog in 1964. It took hours to set up the machine for a new sound. Among the first music performed on this synthesizer are the record "The well-tempered synthesizer" and "Switched-on Bach" by Walter Carlos (Wendy Carlos since a sex change operation).

Moog also established standards for control interfacing, with a logarithmic 1-volt-per-octave pitch control and a separate pulse triggering signal.

Other commercial synthesizer manufacturers included ARP, who also started with modular synthesizers before producing all-in-one instruments.

Miniaturization of the components made it possible, in the 1970s, for synthesizers to become self-contained and movable. They began to be used in live performances.

Electronic organs vs. synthesizers

(Hammond organ etc... to be written)

Early polyphonic synthesizers

(Polymoog, Oberheim 4-voice)

Microprocessor controlled analog synthesizers

(Sequential Circuits Prophet synth?)

MIDI control

Synthesizers became more usable with the invention in 1985 of MIDI, a digital control interface, and later with the creation of all-digital synthesizers and samplers.

(this page is of course incomplete. please fill out)

Early academic digital synthesis research

(Stanford, IRCAM etc)

Early commercial digital synthesizers: the FM synthesis era

(Yamaha DX synthesizer... 80's FM sound)

Samplers and sampling

One kind of synthesizer, which starts with a recording of an existing sound, which is then replayed at a range of pitches, is called a sampler.

An early form of sampler was an instrument called the 'Mellotron' which used individual pre-recorded tape loops, one under each key on the keyboard. Mellotrons required a lot of maintenance, but had a characteristic sound that was used on many 1970s records by groups such as Yes.

The emergence of the digital sampler made sampling far more practical, and as samplers added progressively more digital processing to their recorded sounds, they began to merge into the mainstream of modern digital synthesizers.

(the earliest samplers: examples)

(sampling and hip-hop: DJ-ing)

(techno and other dance music)

The modern digital synthesizer

Most modern synthesizers are now completely digital, including those which model analog synthesis using digital techniques. Digital synthesizers use digital signal processing (DSP) techniques to make musical sounds. Some digital synthesizers now exist in the form of 'softsynth' software that synthesizes sound using conventional PC hardware. Others typically use specialized DSP hardware.

(to be written)

Software-only synthesis

(to be written)

Commercial synthesizer manufacturers

Notable synthesizer manufacturers past and present include:

Classic synthesizer designs

This is intended to be a list of classic instruments which marked a turning point in musical sound or style, potentially worth an article of their own. They are listed with the names of performers or styles associated with them.