Polyphony (instrument)
Encyclopedia
Polyphony Instruments that are not capable of polyphony are monophonic
Monophony
In music, monophony is the simplest of textures, consisting of melody without accompanying harmony. This may be realized as just one note at a time, or with the same note duplicated at the octave . If the entire melody is sung by two voices or a choir with an interval between the notes or in...

.

Synthesizer

Most of early synthesizers were monophonic musical instruments which can play only one note at a time, and are often called monosynth
Monosynth
A monophonic synthesizer or monosynth is a synthesizer that produces only one note at a time, making it smaller and cheaper than a polysynth, a synthesizer which can play multiple notes at once; most later synthesizers are polysynths....

as opposed to polysynth. For example, Minimoog
Minimoog
The Minimoog is a monophonic analog synthesizer, invented by Bill Hemsath and Robert Moog. It was released in 1970 by R.A. Moog Inc. , and production was stopped in 1981. It was re-designed by Robert Moog in 2002 and released as Minimoog Voyager.The Minimoog was designed in response to the use of...

 has three oscillators which are settable in arbitrary intervals, but it can play only one note at a time (with a timbre consists of three pitches of fixed-intervals).

Duophonic synthesizer

Duophonic
Duophonic
*In synthesizers, capable of sounding two voices, or notes, at a time. Compare: monophonic, polyphonic.*Duophonic is also a term used to refer to a sound process by which a monaural recording is turned into a kind of "fake stereo" by splitting the signal into two channels, delaying the left and the...

 synthesizers, such as the ARP Odyssey
ARP Odyssey
The ARP Odyssey was an analog synthesizer introduced in 1972. Responding to pressure from Moog Music to create a portable, affordable "performance" synthesizer, ARP scaled down its popular 2600 synthesizer and created the Odyssey, which became the best-selling synthesizer they made.The Odyssey is...

 and Formanta Polivoks
Polivoks
The Polivoks is a duophonic, analog synthesizer manufactured and marketed in the Soviet Union between 1982 and 1990...

 built in the 1970s, has a capability to play independent two pitches at a time. These synthesizers have (at least) two oscillators separately controllable, and duophonic keyboard that can generate two control voltage signals for lowest- and highest-note. When two or more keys are pressed simultaneously, lowest- and highest-note will be heard. When only one key is pressed, both oscillators are assigned to one note, and possibly more complex sound will be heard.

Polyphonic synthesizers

The earliest polyphonic synthesizers were built in the late 1930s, but the concept did not become popular until the mid 1970s. Harald Bode
Harald Bode
Harald Bode was a German engineer and pioneer in the development of electronic music instruments.- Biography :...

's “Warbo Formant Orguel”, developed in 1937, was an archetype of a voice allocation polyphonic synthesizer. Novachord
Novachord
The Novachord is often considered to be the world's first commercial polyphonic synthesizer. All-electronic, incorporating many circuit and control elements found in modern synths, and using subtractive synthesis to generate tones, it was designed by John M. Hanert, Laurens Hammond and C. N....

 by Hammond Organ Company
Hammond organ
The Hammond organ is an electric organ invented by Laurens Hammond in 1934 and manufactured by the Hammond Organ Company. While the Hammond organ was originally sold to churches as a lower-cost alternative to the wind-driven pipe organ, in the 1960s and 1970s it became a standard keyboard...

, released in 1939, is a forefather product of octave divider synthesizer and electronic organs. It uses frequency divider technology to generate polyphony, and about one thousand Novachords were manufactured until 1942.

In the early 1970s, Allen Organ Company, E-mu Systems
E-mu Systems
E-mu Systems, Inc. is a synthesizer maker and pioneer in samplers and low-cost digital sampling music workstations.-History:Founded in 1971 by Scott Wedge and Dave Rossum, E-mu began making modular synthesizers...

 and Yamaha
Yamaha
Yamaha may refer to:* Yamaha Corporation, a Japanese company with a wide range of products and services** Yamaha Motor Company, a Japanese motorized vehicle-producing company...

 independently developed digital keyboard scanning
Keyboard matrix (music)
Most electronic keyboards used in synthesizers, electronic organs, and digital pianos use a keyboard matrix circuit to connect the switches for each key. In this matrix circuit, the rows and columns are made up of wiring...

technology, and the results were known as Oberheim 2/4/8-voices
Oberheim polyphonic
The Oberheim polyphonic is an analog music synthesizer that was produced from 1974 to 1979 by Oberheim electronics. Tom Oberheim, the founder, knew that musicians needed a way to play chords on the synthesizers that were becoming popular in all styles of music in the 1970s. Except for huge, custom,...

 licensed by E-mu Systems and Yamaha GX-1
Yamaha GX1
The Yamaha GX-1, first released as Electone GX-707 It's rumored that when Yamaha realized the model number shared the designation of Boeing 707 aircraft, they changed it to GX-1. Note the basic design of GX-1 followed the released in 1970., is an analog polyphonic synthesizer developed by Yamaha...

.

Synths using octave divider

A forefather of octave divider synth and electronic organs.
|Moog Polymoog
Polymoog
The Polymoog is a polyphonic analog synthesizer that was manufactured by Moog Music from 1975 to 1980. The Polymoog was based on divide-down oscillator technology similar to electronic organs and string synthesizers of the time, and this led to a certain lack of flexibility compared to later...

(1975)
Octave divider technology similar to Novachord was used.
|Korg
Korg
is a Japanese multinational corporation that manufactures electronic musical instruments, audio processors and guitar pedals, recording equipment, and electronic tuners...

 PE-1000
(1976)
Polyphonic ensemble keyboard consists with one synth per key (totally 60 synthesizers).
|Korg PS-3300
Korg PS-3300
The Korg PS-3300 is a polyphonic analog synthesizer produced by Korg, between 1977 and 1981.- History :The Korg PS-3300 is one of the biggest and rarest synthesizers ever made. Only around 50 units were produced by Korg over a 4-year period from 1977 to 1981 after which it was discontinued...

(1977)
Although it uses octave divider, it contains three synths per key.
|}

Synths using voice allocation

Voice allocation technology was used to assign limited 8-voices per manual into notes.
|E-mu Modular System
E-mu Modular System
The E-mu Modular System is an analog modular synthesizer built by E-mu Systems in the early 1970s. It competed with synthesizers such as the ARP 2500, ARP 2600, and Moog modular synthesizers, although E-mu designed the instruments for mostly universities and notable musicians who submitted custom...

(1972)
In 1974, E-mu released polyphonic keyboards for it.
|Oberheim 4voice
Oberheim polyphonic
The Oberheim polyphonic is an analog music synthesizer that was produced from 1974 to 1979 by Oberheim electronics. Tom Oberheim, the founder, knew that musicians needed a way to play chords on the synthesizers that were becoming popular in all styles of music in the 1970s. Except for huge, custom,...

(1975)
Polyphonic technology was licensed by E-mu Systems.
|Sequential Circuites Prophet-5 (1977) is one of the most popular polyphonic synth featuring patch memories, also used E-mu's technology.
|}

Number of voices

One notable early polyphonic synthesizer was the Sequential Circuits
Sequential Circuits
Sequential Circuits Inc. was a California-based synthesizer company that was founded in the early 1970s by Dave Smith and sold to Yamaha Corporation in 1987. The company, throughout its lifespan, pioneered many groundbreaking technologies and design principles that are often taken for granted in...

 Prophet 5, which was released in 1977 and had five-voice polyphony. Six-voice polyphony was standard by the middle 1980s. With the advent of digital synthesizers, 16-voice polyphony became standard by the late 1980s. 64-voice polyphony was common by the middle 1990s and 128-note polyphony arrived shortly after. There are several reasons for providing such large numbers of simultaneous notes:
  • Even with only ten fingers, it is possible to play more than ten notes at once. Notes may continue to sound even after a key is released. The synthesizer's resources may still be in use to produce the sound of the previously struck notes tapering off, especially when a sustain pedal is used.

  • A "sound" (also called a "timbre" or "patch") may be generated by more than one oscillator or sound-source to allow more complicated sounds to be produced. A synthesizer with 16 oscillators may be capable of 16-note polyphony only when simple, single-oscillator sounds are produced. If a particular patch requires four oscillators, then the synthesizer is only capable of four-note polyphony.

  • Synthesizers may be configured to produce multiple timbres (multitimbral
    Multitimbral
    Monotimbral is usually used in reference to electronic synthesisers which can produce a single timbre at a given pitch upon pressing a single or multiple keys .An electronic musical instrument may be...

    ), particularly necessary when sounds are layered or sequenced
    Sequencer
    Sequencer may refer to:Arts and Entertainment* Sequencer , 1976* Sequencer , 1996Technology* DNA sequencer, a machine used to automatically produce a sequence readout from a biological DNA sample...

    . Multitimbral instruments are always polyphonic but polyphonic instruments are not necessarily multitimbral. Some multitimbral instruments have a feature which allows the user to specify the amount of polyphony reserved or allowed for each timbre.

Note priority of synthesizer

Synthesizers generally use oscillators to generate the electric signal that forms the basis of the sound, often with a keyboard
Musical keyboard
A musical keyboard is the set of adjacent depressible levers or keys on a musical instrument, particularly the piano. Keyboards typically contain keys for playing the twelve notes of the Western musical scale, with a combination of larger, longer keys and smaller, shorter keys that repeats at the...

 to trigger the oscillators. However multiple oscillators working independently are a considerable challenge to implement. To double the polyphony, not only must the number of oscillators be doubled but the electronics must also function as a switch connecting keys to free oscillators instantaneously, implementing an algorithm
Algorithm
In mathematics and computer science, an algorithm is an effective method expressed as a finite list of well-defined instructions for calculating a function. Algorithms are used for calculation, data processing, and automated reasoning...

 that decides which notes are turned off if the maximum number of notes is already sounding when an additional key is pressed. There are several ways to implement this:
  • Turn off the first note sounded and use the newly freed oscillator to play the new note. With last note priority, priority is based on the order in which keys are played. When new notes are triggered while all voices are playing, the synthesizer frees up polyphony by ending the earliest played sounding note. This is the default mode on most synthesizers.
  • Turn off the last note sounded and use the newly freed oscillator to play the new note
  • Ignore the newly depressed note. With first note priority, earlier notes are not cut off to make room for later ones, and once maximum polyphony has been reached, the person playing the instrument must stop playing one or more notes in order to trigger new ones.
  • In highest note priority, new notes that are higher in pitch than ones being already played replace currently playing notes from the lowest on up.
  • Lowest note priority works in the same way, but cutting notes from the highest down.


Modern synthesizers and sampler
Sampler (musical instrument)
A sampler is an electronic musical instrument similar in some respects to a synthesizer but, instead of generating sounds, it uses recordings of sounds that are loaded or recorded into it by the user and then played back by means of a keyboard, sequencer or other triggering device to perform or...

s may use additional, multiple and/or user-configurable criteria to decide which notes sound.

Acoustic keyboard instruments

Almost all classical keyboard instruments are polyphonic. Examples include the piano
Piano
The piano is a musical instrument played by means of a keyboard. It is one of the most popular instruments in the world. Widely used in classical and jazz music for solo performances, ensemble use, chamber music and accompaniment, the piano is also very popular as an aid to composing and rehearsal...

, harpsichord
Harpsichord
A harpsichord is a musical instrument played by means of a keyboard. It produces sound by plucking a string when a key is pressed.In the narrow sense, "harpsichord" designates only the large wing-shaped instruments in which the strings are perpendicular to the keyboard...

, organ
Organ (music)
The organ , is a keyboard instrument of one or more divisions, each played with its own keyboard operated either with the hands or with the feet. The organ is a relatively old musical instrument in the Western musical tradition, dating from the time of Ctesibius of Alexandria who is credited with...

 and clavichord
Clavichord
The clavichord is a European stringed keyboard instrument known from the late Medieval, through the Renaissance, Baroque and Classical eras. Historically, it was widely used as a practice instrument and as an aid to composition, not being loud enough for larger performances. The clavichord produces...

. These instruments feature a complete sound-generating mechanism for each key in the keybed (e.g., a piano has a string and hammer for every key, and an organ has at least one pipe for each key.) When any key is pressed, the note corresponding to that key will be heard as the mechamism is activated.

Some clavichords do not have a string for each key. Instead, they will have a single string which will be fretted by several different keys. Out of the keys that share a single string, only one may sound at a time.

Electric keyboard instruments

The electric piano
Rhodes piano
The Rhodes piano is an electro-mechanical piano, invented by Harold Rhodes during the fifties and later manufactured in a number of models, first in collaboration with Fender and after 1965 by CBS....

 and clavinet
Clavinet
A Clavinet is an electrically amplified keyboard instrument manufactured by the Hohner company. It is essentially an electronically amplified clavichord, analogous to an electric guitar. Its distinctive bright staccato sound has appeared particularly in funk, disco, rock, and reggae songs.Various...

 rely on the same principles to achieve polyphonic operation. An electric piano has a separate hammer, vibrating metal tine and electrical pickup
Pickup
Pickup, Pick up or Pick-up may refer to:-Technology:*Magnetic cartridge, also known as pickup, a transducer used for the playback of gramophone records on a turntable or phonograph...

 for each key.

With a few exceptions, electric organs consist of two parts: an audio-generating system and a mixing system. The audio-generating system may be electronic (consisting of oscillators and octave dividers) or it may be electromechanical (consisting of tonewheel
Tonewheel
A tonewheel is a simple electromechanical apparatus for generating electronic musical notes. The tonewheel assembly consists of a synchronous AC motor and an associated gearbox that drives a series of rotating disks...

s and pickups), and it sends a large number of audio outputs to a mixer. The stops or drawbars on the organ modify the signal sent from the audio-generating system, and the keyboard switches the mixer's channels on and off. Those channels which are switched on are heard as notes corresponding to the depressed keys.

Classical instruments

Stringed instruments may be polyphonic if they have a separate string for each note to be played. The harp has a large number of strings, one for each note in the scale, so it is polyphonic; The guitar has multiple strings and is usually chorded and not played one string at a time, so it is polyphonic; The violin has multiple strings, but usually only one is bowed at a time, so the violin family of instruments are considered to be monophonic.

Some eastern instruments include strings which are fretted and plucked like those on a guitar, plus secondary strings which resonate and provide reverberation on a few key notes. This is technically not polyphony, but it can be used to simulate polyphony.

Newer instruments

The electric guitar, just like the classical guitar, is polyphonic, as are the various guitar derivatives that have turned up (including the harpejji
Harpejji
The harpejji is an electric stringed musical instrument developed in 2007 by Tim Meeks, founder of Marcodi Musical Products, and is a descendant of the StarrBoard. The instrument aims to bridge the gap in sound and technique between the guitar and the piano...

 and the Chapman stick
Chapman Stick
The Chapman Stick is an electric musical instrument devised by Emmett Chapman in the early 1970s. A member of the guitar family, the Chapman Stick usually has ten or twelve individually tuned strings and has been used on music recordings to play bass lines, melody lines, chords or textures...

).

Woodwinds and brass

Although polyphonic wind instruments are relatively rare, they do exist. Multichambered ocarinas are manufactured in a number of varieties, including double, triple, and quadruple ocarinas, which use multiple chambers to extend the ocarina's otherwise limited range, but also enable the musician to play more than one note simultaneously. Harmonic ocarinas are specifically designed for polyphony, and in these instruments the range of the chambers usually overlap to some extent. Cross-fingering enables a single chamber to span an entire octave or more.

Recorders can also be doubled for polyphony. There are two types of double recorder; the drone type and the polyphonic type. In the drone type, one tube is tuned exactly like a regular recorder with a range of approximately two octaves, and the other tube is a drone and plays the tonic note of the scale. The polyphonic recorder has two tubes with a range of one major sixth. With overblowing, some notes can be played an octave higher, but it is not possible to achieve the range of an entire octave in one tube with these instruments.

See also

  • Synthesizer
    Synthesizer
    A synthesizer is an electronic instrument capable of producing sounds by generating electrical signals of different frequencies. These electrical signals are played through a loudspeaker or set of headphones...

  • Keyboard matrix (music)
    Keyboard matrix (music)
    Most electronic keyboards used in synthesizers, electronic organs, and digital pianos use a keyboard matrix circuit to connect the switches for each key. In this matrix circuit, the rows and columns are made up of wiring...

  • Electronic musical instrument#Polyphony

  • Monophonic (synthesizers)
  • Duophonic
    Duophonic
    *In synthesizers, capable of sounding two voices, or notes, at a time. Compare: monophonic, polyphonic.*Duophonic is also a term used to refer to a sound process by which a monaural recording is turned into a kind of "fake stereo" by splitting the signal into two channels, delaying the left and the...

  • Paraphony
    Paraphony
    Paraphony is the property of an electronic musical instrument that can produce multiple notes or voices, but falls short of being truly polyphonic because the voices are not fully independent since they share at least one common element...

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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