Extended vocal technique
Particularly famous examples of extended vocal technique can be found in the music of Luciano Berio, John Cage, George Crumb, Peter Maxwell Davies, Hans Werner Henze, György Ligeti, Demetrio Stratos, Meredith Monk, Giacinto Scelsi, Arnold Schoenberg, Salvatore Sciarrino, Karlheinz Stockhausen, Tim Foust, Avi Kaplan, and Trevor Wishart.[1] Although used in the traditional music of Mongolia, Tuva, and Tibet, overtones have also been used in the contemporary compositions of Karlheinz Stockhausen (Stimmung),[2] as well as in the work of David Hykes.[3] By carefully controlling the configurations of the vocal cords, a singer may obtain "undertones" which may produce period doubling, tripling or a higher degree of multiplication;[citation needed] this may give rise to tones that fairly coincide with those of an inverse harmonic series.[citation needed] This technique features in the 1968 composition Versuch über Schweine by the German composer Hans Werner Henze.Besides producing sounds with the mouth, singers can be required to clap or snap their fingers, shuffle their feet, or slap their body.When inhaled, helium changes the resonant properties of the human vocal track resulting in a very high squeaky voice.[4][failed verification] Amplification, such as microphone or even megaphone, possibly with electronic distortion of the voice, is frequently used in contemporary composition.