Microtonal music is music using microtones—intervals of less than an equally spaced semitone. Microtonal music can also refer to music which uses intervals not found in the Western system of 12 equal intervals to the octave.
Microtonal music can refer to all music which contains intervals smaller than the conventional contemporary Western semitone. The term implies music containing very small intervals but can include any tuning that differs from the western 12-tone equal temperament. Traditional Indian systems of 22 śruti; Indonesian gamelan music; Thai, Burmese, and African musics, and music using just intonation, meantone temperament, or other alternative tunings may be considered microtonal.
(Griffiths and Lindley 1980; Griffiths, Lindley, and Zannos 2001). Microtonal variation of intervals is standard practice in the African-American musical forms of spirituals, blues and jazz (Cook and Pople 2004, 124–26).
Many microtonal equal divisions of the octave have been proposed, usually (but not always) in order to achieve approximation to the intervals of just intonation. (Griffiths and Lindley 1980; Griffiths, Lindley, and Zannos 2001)
Terminology other than "microtonal" is used by theorists and composers. Ivan Wyschnegradsky used the term ultra-chromatic for intervals smaller than the semitone and infra-chromatic for intervals larger than the semitone (Wyschnegradsky 1972, 84–87). Ivor Darreg proposed the term xenharmonic. (See xenharmonic music).
The Hellenic civilizations of ancient Greece left fragmentary records of their music—c.f., the Delphic Hymns. The ancient Greeks approached the creation of different musical intervals and modes by dividing and combining tetrachords, recognizing three genera of tetrachords: the enharmonic, the chromatic, and the diatonic. Ancient Greek intervals were of many different sizes, including microtones. The enharmonic genus in particular featured intervals of a distinctly "microtonal" nature, which were sometimes smaller than 50 cents, less than half of the contemporary Western semitone of 100 cents. In the ancient Greek enharmonic genus, the tetrachord contained a semitone of varying sizes (approximately 100 cents) divided into two such smaller, microtonal, intervals; in conjunction with a larger interval of roughly 400 cents, these intervals comprised the perfect fourth (approximately 498 cents, or the ratio of 4/3 in just intonation) (West 1992, 160–72).
Guillaume Costeley's "Chromatic Chanson", "Seigneur Dieu ta pitié" of 1558 used 1/3 comma meantone and explored the full compass of 19 pitches in the octave. (Lindley 2001a).
The Italian Renaissance composer and theorist Nicola Vicentino (1511–1576) worked with microtonal intervals building a keyboard with 36 keys to the octave, known as the archicembalo. Theoretically an interpretation of ancient Greek tetrachordal theory, in effect Vincento presented a circulating system of quarter-comma meantone, maintaining major thirds tuned in Just intonation in all keys (Barbour 1951, 117–18).
Jacques Fromental Halévy composed a quarter-tone work for soli, choir and orchestra "Prométhée enchaîné" in 1849.
In the 1910s and 1920s, quarter tones (24 equal pitches per octave) received attention from composers as Charles Ives, Julián Carrillo, Alois Hába, Ivan Wyschnegradsky, and Mildred Couper. Erwin Schulhoff gave classes in quarter-tone composition at the Prague Conservatory.
Alexander John Ellis, who in the 1880s produced a translation with extensive footnotes and appendices to Helmholtz's On the Sensations of Tone, proposed an elaborate set of exotic just intonation tunings and non-harmonic tunings (Helmholtz 1885, 514–27). Ellis also studied the tunings of non-Western cultures and, in a report to the Royal Society, stated that they did not use either equal divisions of the octave or just intonation intervals (Ellis 1884). Ellis inspired Harry Partch immensely (Partch 1979, vii).
During the Exposition Universelle of 1889, Claude Debussy heard a Balinese gamelan performance and was exposed to non-Western tunings and rhythms. Some scholars have ascribed Debussy's subsequent innovative use of the whole-tone (6 equal pitches per octave) tuning in such compositions as the Fantaisie for piano and orchestra and the Toccata from the suite Pour le piano to his exposure to the Balinese gamelan at the Paris exposition (Lesure 2001), and have asserted his rebellion at this time "against the rule of equal temperament" and that the gamelan gave him "the confidence to embark (after the 1900 world exhibition) on his fully characteristic mature piano works, with their many bell- and gong-like sonorities and brilliant exploitation of the piano’s natural resonance" (Howat 2001). Still others have argued that Debussy's works like L'Isle joyeuse, La Cathédrale engloutie, Prélude à l'après-midi d'un faune, La Mer, Pagodes, Danseuses de Delphes, and Cloches à travers les feuilles are marked by a more basic interest in the microtonal intervals found between the higher members of the overtone series, under the influence of Hermann Helmholtz's writings (Don 1991, 69 et passim). Berliner's introduction of the phonograph in the 1890s allowed much non-Western music to be recorded and heard by Western composers, further spurring the use of non-12-equal tunings.
Experimenting with the violin in 1895, Julián Carrillo (1875–1965) distinguished sixteenth tones, i.e., sixteen clearly different sounds between the pitches of G and A emitted by the fourth violin string. He named these microtonal distinctions Sonido 13 (the thirteenth sound) and wrote on music theory and the physics of music. He invented a simple numerical musical notation to represent scales based on any division of the octave, such as thirds, fourths, quarters, fifths, sixths, sevenths, and so on (even if Carrillo wrote, most of the time, for quarters, eights, and sixteenths combined, the notation is intended to represent any imaginable subdivision). He invented new musical instruments, and adapted other instruments to produce microintervals. He composed a large amount of microtonal music and recorded about 30 of his compositions.
Major microtonal composers of the 1920s and 1930s include Alois Hába (quarter tones, or 24 equal pitches per octave, and sixth tones), Julian Carillo (24 equal, 36, 48, 60, 72, and 96 equal pitches to the octave embodied in a series of specially custom-built pianos), Ivan Wyschnegradsky (third tones, quarter tones, sixth tones and twelfth tones, non octaving scales) and the early works of Harry Partch (just intonation using frequencies at ratios of prime integers 3, 5, 7, and 11, their powers, and products of those numbers, from a central frequency of G-196) (Partch 1979, chapt. 8, "Application of the 11 Limit", 119–37).
Prominent microtonal composers or researchers of the 1940s and 1950s include Adriaan Daniel Fokker (31 equal tones per octave), Partch (continuing to build his handcrafted orchestra of microtonal just intonation instruments), and Eivind Groven.
Barbara Benary also formed Gamelan Son of Lion around this period, and Lou Harrison was instrumental in creating American gamelan orchestras at Mills College. In Europe, the "Spectralists" in Paris created their first works from 1973 on with an extensive use of microtonal harmony. The main composers were Hugues Dufourt, Gérard Grisey, Tristan Murail and Michael Levinas; see also the Parisian ensemble "L'itinéraire".
Digital synthesizers from the Yamaha TX81Z (1987) on and inexpensive software synthesizers have contributed to the ease and popularity of exploring microtonal music.
Microtonalism in electronic music 
Electronic music facilitates the use of any kind of microtonal tuning, and sidesteps the need to develop new notational systems (Griffiths, Lindley, and Zannos 2001). In 1954, Karlheinz Stockhausen built his electronic Studie II on an 81-step scale starting from 100 Hz with the interval of 51/25 between steps (Stockhausen 1964, 37), and in Gesang der Jünglinge (1955–56) he used various scales, ranging from seven up to sixty equal divisions of the octave (Decroupet and Ungeheuer 1998, 105, 116, 119–21). In 1955, Ernst Krenek used 13 equal-tempered intervals per octave in his Whitsun oratorio, Spiritus intelligentiae, sanctus (Griffiths, Lindley, and Zannos 2001).
In 1986, Wendy Carlos experimented with many microtonal systems including just intonation, using alternate tuning scales she invented for the album Beauty In the Beast. "This whole formal discovery came a few weeks after I had completed the album, Beauty in the Beast, which is wholly in new tunings and timbres" (Carlos 1989–96).
Microtonalism in rock music 
A form of microtone known as the blue note is an integral part of rock music and one of its predecessors, the blues. The blue notes, located on the third, fifth, and seventh notes of a diatonic major scale, are flattened by a variable microtone (Ferguson 1999, 20).
See also 
Western microtonal pioneers 
Pioneers of modern Western microtonal music include:
- Henry Ward Poole (keyboard designs, 1825–1890)
- Eugène Ysaÿe (Belgium, U.S.A., 1858–1931, used quarter tones in several of the Sonatas for Solo Violin, Op. 27)
- Charles Ives (U.S.A., 1874–1954, quartertones)
- Julián Carrillo (Mexico, 1875–1965) many different equal temperaments, look here or here (mostly Spanish but some English too)
- Béla Bartók (Hungary, 1881–1945, rare uses of quartertones)
- George Enescu (Romania, France, 1881–1955) (in Œdipe to suggest the enharmonic genus of ancient Greek music, and in the Third Violin Sonata, as inflections characteristic of Romanian folk music)
- Karol Szymanowski (Poland, 1882–1937, used quartertones on the violin in Myths Op. 30, 1915)
- Percy Grainger (Australia, 1882–1961, particularly works for his "free music machine")
- Edgard Varèse (France, U.S.A., 1883–1965, quartertones)
- Luigi Russolo (Italy, 1885–1947, used quartertones and eighth tones on the Intonarumori, noise instruments)
- Mildred Couper (U.S.A., 1887–1974, quartertones)
- Alois Hába (Czechoslovakia, 1893–1973, quartertones and other equal temperaments)
- Ivan Wyschnegradsky (U.S.S.R. (Russia), France, 1893–1979, quartertones, twelfth tones and other equal temperaments)
- Harry Partch (U.S.A., 1901–1974, just intonation)
- Eivind Groven (Norway, 1901–1977, 53ET)
- Henk Badings (The Netherlands, 1907–1987, 31ET)
- Maurice Ohana (France, 1913–1992, third tones (18-equal) temperament and quarter tones (24ET) most particularly)
- Giacinto Scelsi (Italy, 1905–1988, intuitive linear tone deviations, quartertones, eighth tones)
- Lou Harrison (U.S.A., 1917–2003, just intonation)
- Ivor Darreg (U.S.A., 1917–1994)
- Jean-Etienne Marie (France, 1919–1989, many different equal temperaments: 18ET, 24ET, 30ET, 36ET, 48ET, 96ET most particularly and polymicrotonality)
- Franz Richter Herf (Austria, 1920–1989, 72-equal temperament, "ekmelic" music)
- Iannis Xenakis (Greece, France, 1922–2001, quarter and third tones most particularly, occasionally eighth tones)
- György Ligeti (Hungary, 1923–2006, Ramifications in quartertone tuning, natural harmonics in his Horn Trio, later just intonation in his solo concertos)
- Luigi Nono (Italy, 1924–1990, quartetones, eighth tones and 16th tones)
- Claude Ballif (France, 1924–2004, quartertones)
- Tui St. George Tucker (1924–2004)
- Pierre Boulez (France, b. 1925) (first example of serial music with quartertones in his pieces Visage Nuptial and Polyphonie X, but soon after abandoning microtonal elements)
- Karlheinz Stockhausen (Germany, 1928–2007, in his electronic works many microtonal concepts, non-octaving scales in Studie II, just intonation in Gruppen and Stimmung, microtonal instrumental and vocal writing throughout Licht)
- Ben Johnston (U.S.A., b. 1926, extended just intonation)
- Ezra Sims (U.S.A., b. 1928, 72-tone equal temperament)
- Erv Wilson (b. 1928)
- Alvin Lucier (U.S.A., b. 1931)
- Joel Mandelbaum (U.S.A., b. 1932)
- Krzysztof Penderecki (Poland, b. 1933, quartertones)
- Easley Blackwood (b. 1933)
- Alain Bancquart(France, b.1934) (quarter tones and 16th tones)
- James Tenney (U.S.A., 1934–2006, just intonation, 72-tone equal temperament)
- Terry Riley (U.S.A., b. 1935, just intonation)
- La Monte Young (U.S.A., b. 1935, just intonation)
- John Corigliano (U.S.A., b. 1938, quarter tones)
- Douglas Leedy (b. 1938, just intonation, meantone)
- Wendy Carlos (U.S.A., b. 1939, non-octaving scales)
- Bruce Mather (Canada, b.1939, different equal temperaments, following Wyschnegradsky)
- Brian Ferneyhough (Great Britain, b. 1943, quartertones, 31ET in Unity Capsule for solo flute,1976)
Recent microtonal composers 
- Clarence Barlow (b. 1945)
- Gérard Grisey (1946–1998) (spectral approach to microintervals, quartertones, eighth tones)
- Max Méreaux (b. 1946)
- Tristan Murail (b. 1947) (spectral approach to microintervals, quartertones, eighth tones)
- Claude Vivier (1948–1983)
- Glenn Branca (b. 1948)
- Dean Drummond (b. 1949) (Harry Partch's instruments currently in his possession)
- Lasse Thoresen (b. 1949)
- Greg Schiemer (b. 1949)
- Warren Burt (b. 1949)
- Manfred Stahnke (b. 1951)
- Kraig Grady (b. 1952) (invented acoustic instruments in just intonation & recurrent sequences)
- Rhys Chatham (b. 1952)
- David First (b. 1953)
- Georg Friedrich Haas (b. 1953)
- James Wood (b. 1953)
- Paul Dirmeikis (b. 1954)
- Pascale Criton (b. 1954) (different equal temperaments, most particularly very dense ETs such as the 96ET)
- Stephen James Taylor (b. 1954)
- Kyle Gann (b. 1955)
- Pascal Dusapin (b. 1955) (different equal temperaments, notably the 48ET)
- Johnny Reinhard (b. 1956) (different equal temperaments, just intonation, polymicrotonally)
- Eric Mandat (b. 1957)
- Erling Wold (b. 1958)
- Michael Bach Bachtischa (b. 1958)
- Martin Smolka (b. 1959)
- Georg Hajdu (b. 1960)
- William Susman (b. 1960)
- Daniel James Wolf (b. 1961)
- François Paris (b. 1961)
- Harold Fortuin (b. 1964)
- Marc Sabat (b. 1965)
- Georges Lentz (b. 1965)
- Jeffrey Ching (b. 1965) (quartertones, ancient Chinese tunings, e.g. circle-of-fifths and just intonation)
- Geoff Smith (b. 1966)
- Elaine A. Walker (b. 1968)
- Yitzhak Yedid (b. 1971)
- Adam Silverman (b. 1973)
- Yuri Landman (b. 1973)
- Kristoffer Zegers (b. 1973)
- Saman Samadi (b. 1984)
- Michael Waller (b. 1985)
Microtonal researchers 
- Christiaan Huygens (1629–1695)
- Julián Carrillo (1875–1965)
- Adriaan Daniël Fokker (1887–1972)
- Ivan Wyschnegradsky (1893–1979)
- Alois Hába (1893–1973)
- Harry Partch (1901–1974)
- Alain Daniélou (1907–1994)
- Jean-Etienne Marie (1917–1989)
- Erv Wilson (b. 1928)
- Joel Mandelbaum (b. 1932)
- James Tenney (1934–2006)
- Clarence Barlow (b. 1945)
- Gene Ward Smith (b. 1947)
- Valeri Brainin (b. 1948)
- Jacques Dudon (b. 1951)
- William Sethares (b. 1955)
- Georg Hajdu (b. 1960)
- Bob Gilmore (b. 1961)
- Marc Sabat (b. 1965)
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- Loli, Charles. 2008. " Microtonalismo". (Article on alternative tuning in Peruvian music)
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