This article needs additional citations for verification. (June 2022)
Overtone singing, also known as overtone chanting, harmonic singing, polyphonic overtone singing, or diphonic singing, is a set of singing techniques in which the vocalist manipulates the resonances of the vocal tract to arouse the perception of additional separate notes beyond the fundamental frequency that is being produced.
From a fundamental pitch, made by the human voice, the belonging harmonic overtones can be selectively amplified by changing the vocal tract: the dimensions and the shape of the resonant cavities of the mouth and the pharynx. That resonant tuning allows singers to create more than one pitch at the same time (the fundamental and one or more selected overtones) and usually generates a single fundamental frequency with their vocal folds.
Overtone singing should not be confused with throat singing although many throat singing techniques include overtone singing. As mentioned, overtone singing involves the careful manipulations of the vocal tract, and throat singing is mostly related to the voice source.
Mongolia and Buryatia
It is thought that the art of overtone singing originated in southwestern Mongolia in today's Khovd Province and Govi Altai region. Nowadays, overtone singing is found throughout the country and Mongolia is often considered the most active center of overtone singing in the world. The most commonly practiced style, called khöömii (Cyrillic: хөөмий), can be divided up into the following categories:
- Uruulyn / labial khöömii
- Tagnain / palatal khöömii
- Khamryn / nasal khöömii
- Bagalzuuryn, khooloin / glottal, throat khöömii
- Tseejiin khondiin, khevliin / chest cavity, stomach khöömii
- Turlegt, khosmoljin khöömii / khöömii combined with long song
Mongolians also use many other singing styles such as karkhiraa (literally 'growling') and isgeree.
Tuvan overtone singing is practiced in the Republic of Tuva (southern Siberia, Russia).
The Tuvan way of singing overtones is based on appreciation of complex sounds with multiple layers or textures, which is how the Tuvans developed a wide range of rhythmic and melodic styles during the centuries. Most of the styles are sung with korekteer (korek 'chest' + teer 'sing'), literally 'to sing with chest voice'. Styles include:
- Kargyraa (which also uses a second sound source made by false vocal folds. This technique is called "false-folds-diplophony")
Other sub-styles include:
- Byrlang (a unique type of vibrato, mainly applied to khöömei and kargyraa styles)
The melodies are traditionally created by using the 6th, 8th, 9th, 10th, 12th, 13th and sometimes the 16th harmonics, which form the major pentatonic scale, so the 7th and 11th harmonics are carefully skipped.
The most peculiar melody, from Tuvan tradition, is "Artii Sayir", mostly performed in kargyraa style.
Altai and Khakassia
Tuva's neighbouring Russian regions, the Altai Republic to the west and Khakassia to the northwest, have developed forms of throat singing called kai (Altay: кай, qay) or khai (Khakas: хай, xay). In Altai, this is used mostly for epic poetry performance, to the instrumental accompaniment of a topshur. Altai narrators (kai-chi) perform in kargyraa, khöömei, and sygyt styles, which are similar to those in Tuva. They also have their own style, a very high harmonics, emerging from kargyraa. Variations of kai are:
- Homei, and
The first well-known kai-chi was Kalkin.
Tibetan Buddhist chanting is a subgenre of throat singing, mainly practiced by monks of Tibet, including Khokhonor (Qinghai) province in the Tibetan plateau area, Tibetan monks of Nepal, Bhutan, India, and various locations in the Himalayan region. Most often the chants hold to the lower pitches possible in throat singing. Various ceremonies and prayers call for throat singing in Tibetan Buddhism, often with more than one monk chanting at a time. There are different Tibetan throat singing styles, such as Gyuke (Standard Tibetan: རྒྱུད་སྐད་ Wylie: rgyud skad), which uses the lowest pitch of voice; Dzoke (མཛོ་སྐད་ mdzo skad); and Gyer (གྱེར་ gyer).
Uzbekistan and Kazakhstan
The poet-musicians of Kazakhstan and the Uzbek region of Karakalpakstan, known as zhirau, employ throat singing in their epic poetry recitations, accompanied by the dombra. Zhirau singers believe that the ability to throat-sing is an innate gift of selected Kazakhs, and that it cannot be taught.
Besides zhirau, there is another form of throat singing called "Kömeimen än aituw (Көмеймен ән айту)" in Kazakhstan. This technique is similar to throat singing in Altai Republic. The Kömeimen än aituw is now being revived by famous Kazakh ethno-folk musical bands HasSak and Turan Ensemble, after Kazakhs believed that this form of throat singing might have been died out because of Russian conquest or rarely practiced or didn't know them at all due to lack of documentings of this practice.
Pakistan, Iran and Afghanistan
Dengbêj, the Kurdish-Yazidi style of bardic chanting, often incorporates overtones as part of the chant, and in a way which is distinct from other forms of overtone singing. There is an article 'Dengbêj - Kurdish long song and overtone singing' by Nick Hobbs in 2020 where he discusses the use of overtones in dengbêj in some detail. Dengbêj is largely a traditional style of Turkish Kurdistan and practitioners are mostly Anatolian. Dengbêj singers often also sing Kurdish folk song but overtones can rarely be heard in Kurdish traditional music outside of dengbêj.
On the island of Sardinia (Italy), especially in the subregion of Barbagia, one of the two different styles of polyphonic singing is marked by the use of throat singing. This kind of choir is called "singing a tenore". The other style, known as cuncordu, does not use throat singing. Cantu a Tenore is practiced by groups of four male singers, each of whom has a distinct role; the 'oche or boche (pronounced /oke/ or /boke/, "voice") is the solo voice, while the mesu 'oche or mesu boche ("half voice"), contra ("against"), and bassu ("bass") – listed in descending pitch order – form a chorus (another meaning of tenore). Boche and mesu boche sing in a regular voice, whereas contra and bassu sings with the use of the false vocal folds, just like the Tuvan Khoomei and Kargyraa techniques. In 2005, Unesco classed the cantu a tenore as an intangible world heritage. The most well known groups who perform the singing a Tenore are from Bitti, Orosei, Oniferi, and Neoneli. Each town has usually more than one group, and their name is based on a specific place, or monument, and then their hometown: for example: Tenore Su Remediu(place) de Orosei(Town).
The Sami people of the northern parts of Sweden, Norway, Finland, and the Kola Peninsula in Russia have a singing genre called yoik. While overtone techniques are not a defining feature of yoik, individuals sometimes utilize overtones in the production of yoik.
The Bashkirs of Bashkortostan, Russia have a style of overtone singing called özläü (sometimes spelled uzlyau; Bashkort Өзләү), which has nearly died out. In addition, Bashkorts also sing uzlyau while playing the kurai, a national instrument. This technique of vocalizing into a flute can also be found in folk music as far west as the Balkans and Hungary.
In Flamenco's Cante Jondo singers often include overtonal colour at the end of phrases. Perhaps originating as a way of facilitating sustain, and then becoming an appreciated ornamentation in its own right. There are many examples but Carmen Linares and Duquende often incorporate overtones.
Some Thembu Xhosa women of South Africa have a low, rhythmic style of throat-singing, similar to the Tuvan Kargyraa style, that is called umngqokolo. It is often accompanied by call-and-response vocals and complicated poly-rhythms.
Canada, United States, and Europe
The 1920s Texan singer of cowboy songs, Arthur Miles, independently created a style of overtone singing, similar to sygyt, as a supplement to the normal yodelling of country western music. Blind Willie Johnson, also of Texas, is not a true overtone singer according to National Geographic, but his ability to shift from guttural grunting noises to a soft lullaby is suggestive of the tonal timbres of overtone singing.
Starting in the 1960s, some musicians in the West either have collaborated with traditional throat singers or ventured into the realm of throat singing and overtone singing, or both. Some made original musical contributions and helped this art rediscover its transcultural universality. As harmonics are universal to all physical sounds, the notion of authenticity is best understood in terms of musical quality. Musicians of note in this genre include Collegium Vocale Köln (who first began using this technique in 1968), Michael Vetter, Tran Quang Hai, David Hykes, Jill Purce, Jim Cole, Ry Cooder, Paul Pena (mixing the traditional Tuvan style with that of American Blues), Steve Sklar, and Kiva (specializing in jazz/ world beat genres and composing for overtone choirs). Others include composer Baird Hersey and his group Prana with Krishna Das (overtone singing and Hindu mantra), as well as Canadian songwriter Nathan Rogers, who has become an adept throat singer and teaches Tuvan throat singing in Winnipeg, Manitoba.
Paul Pena was featured in the documentary Genghis Blues, which tells the story of his pilgrimage to Tuva to compete in their annual throat singing competition. The film won the documentary award at the 1999 Sundance Film Festival, and was nominated for an Oscar in 2000.
Tuvan singer Sainkho Namtchylak has collaborated with free jazz musicians such as Evan Parker and Ned Rothenberg. Lester Bowie and Ornette Coleman have worked with the Tenores di Bitti, and Eleanor Hovda has written a piece using the Xhosa style of singing. DJs and performers of electronic music like The KLF have also merged their music with throat singing, overtone singing, or with the theory of harmonics behind it.
Tran Quang Hai, a researcher on overtone singing since 1969 in Paris, France, has published many articles, videos on overtone singing from 1971. His film "The Song of Harmonics" directed by Hugo Zemp in 1989 obtained 4 international prizes in Estonia (1990) France (1990) and Canada (1991).
David Hykes, a pioneer in new music, contemplative chant and healing sounds, founded Harmonic Chant in New York in 1975, the year he also founded his legendary group, The Harmonic Choir, considered to be one of the world's pre-eminent overtone ensembles.
Wolfgang Saus, from Germany, is considered one of the major teachers/performers of "polyphonic overtone singing" in Europe. Formerly trained as a classical baritone, his unique skills make him instantly recognizable. He's also a renowned composer and arranger of polyphonic overtone singing music for solo voice and choirs.
The Overtone Choir Spektrum from Prague, Czech Republic, is unique among overtone choirs, particularly because it connects traditional choir singing with overtone techniques. It is the only one of its kind in the Czech Republic, and one of only a few in the world. 
MuOM Ecstatic Voices is another unique and peculiar overtone singing choir, as it combines in its own compositions Western overtone singing and Tuvan/Mongolian throat singing techniques (such as kargyraa, khoomei, sygyt, ezengiler, bonbarnadyr, among others). Created in Barcelona in 2008, with 8 singers on average, it has specialised in the creation of overtone polyphonies, (each singer is emitting an overtone) in addition to the polyphony of the fundamentals, creating two distinguishable sound planes.
Sherden Overtone Choir was founded in 2016 in Sardinia by Ilaria Orefice and Giovanni Bortoluzzi. The choir combines Tuvan Throat Singing Styles with Sardinian Throat singing.
Contemporary multi-instrumentalist performer The Suitcase Junket employs a self-taught overtone singing, or throat singing technique in his live and recorded performances.
Several contemporary classical composers have incorporated overtone singing into their works. Karlheinz Stockhausen was one of the first, with Stimmung in 1968. Tran Quang Hai (b.1944), a French national of Vietnamese origin, created the composition "Ve Nguon" with the collaboration of Vietnamese composer Nguyen Van Tuong in 1975, in Paris. "Past Life Melodies" for SATB chorus by Australian composer Sarah Hopkins (b. 1958) also calls for this technique. In Water Passion after St. Matthew by Tan Dun, the soprano and bass soloists sing in a variety of techniques including overtone singing of the Mongolian style.
In 2014 German singer Anna-Maria Hefele went viral on YouTube with her "polyphonic overtone" singing. The Huffington Post has commented on her "amazing ability" and her singing being "utterly bizarre". On 10 October 2014, she was number two on The Guardian's Viral Video Chart, with one online video titled Polyphonic Overtone Singing, which features Hefele as she demonstrates and explains overtones. As of February 2023, this video has received more than 20 million views.
Istanbul-based British singer Nikolai Galen incorporates overtones into his experimental work. They can be heard on his solo album Emanuel Vigeland, the Black Paintings album Screams and Silence and the Hoca Nasreddin album A Headful of Birds.
- Titze 2008; Titze 1994; Pariser & Zimmerman 2004
- Welch, Graham; Sundberg, Johan (2002), Parncutt; McPherson (eds.), "Solo Voice", The Science & Psychology of Music Performance, Oxford University Press, pp. 252–268, doi:10.1093/acprof:oso/9780195138108.003.0016, ISBN 978-0-19-513810-8, retrieved 2021-10-03
- Sklar, 2005
- Deschênes, Bruno (2002-03-04). "Inuit Throat-Singing". Mustrad.org.uk. Retrieved 2008-11-27.
- Margarethe, Adams (2013). "The Fiddle's Voice: Timbre, Musical Learning, and Collaborative Ethnography in Central and Inner Asia". Collaborative Anthropologies. University of Nebraska Press. 6 (1): 149–169. doi:10.1353/cla.2013.0010. S2CID 191364601.
- Bandinu 2006.
- Dr. Dave Dargie "Some recent developments in Xhosa music : activities of the Ngqoko Traditional Xhoa Music Ensemble, and at the University of Fort Hare". Retrieved on 2014-04-23.
- Dr. Dave Dargie "UMNGQOKOLO – Thembu Xhosa – OVERTONE SINGING filmed 1985–1998 in South Africa". Retrieved on 2014-04-23.
- Dargie, Dave. "Xhosa Overtone Singing" The world of South African music: A reader. Cambridge Scholars Press, 2005. 152–155 Google Books Web. 23 Apr. 2014. 
- Miller, Bruce. "Overtone Singing Music". National Geographic. Archived from the original on May 26, 2012. Retrieved February 20, 2012.
- Bellamy and MacLean 2005, 515.
- "German Musician Anna-Maria Hefele Demonstrates Polyphonic Overtone Singing, And It's Amazing". Huffington Post. 7 October 2014. Retrieved 12 October 2014.
- Perraudin, Frances (10 October 2014). "Viral Video Chart". The Guardian. Retrieved 12 October 2014.
- Bandinu, Omar (2006). "Il canto a tenore: dai nuraghi all'Unesco", Siti 2, no.3 (July–September): 16–21.
- Bellamy, Isabel, and Donald MacLean (2005). Radiant Healing: The Many Paths to Personal Harmony and Planetary Wholeness. Buddina, Queensland (Australia): Joshua Books. ISBN 0-9756878-5-9
- Haouli, Janete El (2006). Demetrio Stratos: en busca de la voz-música. México, D. F.: Radio Educación – Consejo Nacional para la Cultura y las Artes.
- Hefele, Eklund & McAllister (2019). "Polyphonic Overtone Singing: An Acoustic and Physiological (MRI) Analysis and a First-person Description of a Unique Mode of Singing". In: Mattias Heldner (ed.): Proceedings from Fonetik 2019, 10–12 June 2019, Stockholm, Sweden. PERILUS XXVII, ISSN 0282-6690, ISBN 978-91-7797-984-5 (print version), ISBN 978-91-7797-985-2 (electronic version), doi:10.5281/zenodo.3246011, pp. 91–96.
- Levin, Theodore C., and Michael E. Edgerton (1999). "The Throat Singers of Tuva". Scientific American 281, no. 3 (September): 80–87.
- Levin, Theodore, and Valentina Süzükei (2006). Where Rivers and Mountains Sing. Bloomington: Indiana University Press. ISBN 0-253-34715-7.
- Pariser, David, and Enid Zimmerman (2004). "Learning in the Visual Arts: Characteristics of Gifted and Talented Individuals," in Handbook of Research and Policy in Art Education, Elliot W. Eisner and Michael D. Day (editors). Lawrence Erlbaum Associates. p. 388. ISBN 978-0-8058-4972-1.
- Saus, Wolfgang (2004). Oberton Singen. Schönau im Odenwald: Traumzeit-Verlag. ISBN 3-933825-36-9 (German).
- Sklar, Steve (2005). "Types of throat singing" ""
- Titze, Ingo R. (1994). Principles of Voice Production. Englewood Cliffs, NJ: Prentice Hall. ISBN 978-0-13-717893-3 Reprinted Iowa City: National Center for Voice and Speech, 2000. (NCVS.org) ISBN 978-0-87414-122-1 .
- Titze, Ingo R. (2008). "The Human Instrument". Scientific American 298, no. 1 (July):94–101. PM 18225701
- Tongeren, Mark C. van (2002). Overtone Singing: Physics and Metaphysics of Harmonics in East and West. Amsterdam: Fusica. ISBN 90-807163-2-4 (pbk), ISBN 90-807163-1-6 (cloth).
- Tran Quang Hai (2018) "50 Years of Research in Vietnamese Traditional Music and Overtone Singing". 462p, Tu Sach Khai Tri, California, USA,ISBN 978-1-7902-3908-5
This article's use of external links may not follow Wikipedia's policies or guidelines. (September 2015)
- Overtone singing used in choir music – Overtone Choir Spektrum & Jan Stanek
- Overtone singing in a water tower – Jim Cole & Spectral Voices
- Audio samples of overtone and throat singing
- Online overtone singing generator
- Ken-Ichi Sakakibara Overtone singing research.
- Harmonic singing vs. normal singing – acoustical measurements and explanation
- Scientific American: The Throat Singers of Tuva
- Types of Throat Singing with Tips /Tuvan Throat-Singing by Steve Sklar
- Observation of the Laryngeal Movements for Throat Singing: Vibration of two pairs of folds in human larynx
- Audio samples of throat singing
- www.overtonesinging.com Overtone Singing with Rollin Rachele
- Tuva throat singers on Flickr
- Kiva's audio samples and information on overtone singing
- Read in Serbian on muzickacentrala.com
- Chukchi throat singing (Zoïa Tagrin'a, Olga Letykaï)
- Overtone singing music
-  – articles, video clips on overtone singing in Tuva, Mongolia, South Africa, Tibet
-  – articles, video clips on overtone singing in the world.