Xenharmonic

Xenharmonic music is music whose tuning systems do not conform to or closely approximate the common 12-tone equal temperament. The term xenharmonic was coined by Ivor Darreg, from xenia (Greek ξενία), "hospitable," and xenos (Greek ξένος) "foreign." He stated: "This writer has proposed the term xenharmonic for music, melodies, scales, harmonies, instruments, and tuning-systems which do not sound like the 12-tone-equal temperament....Xenharmonics is intended to include just intonation and such temperaments as the 5-,7-, and 11-tone, along with the higher-numbered really-microtonal systems as far as one wishes to go."

John Chalmers, author of "Divisions of the Tetrachord", writes: "The converse of this definition is that music which can be performed in 12-tone equal temperament without significant loss of its identity is not truly microtonal." Thus xenharmonic music may be distinguished from the more common twelve-tone equal temperament, as well as some use of just intonation and equal temperaments, by the use of unfamiliar intervals, harmonies, and timbres.

What counts as xenharmonic here however is subjective. As an example, Edward Foote in his program notes for his "6 degrees of tonality" CD, refers to this individual difference in response to the more radical tunings he uses, such as Kinberger and DeMorgan, from "shocking", to "Too subtle to immediately notice", saying "Temperaments are new territory for 20th century ears. The first-time listener may find it shocking to hear the harmony change "color" during modulations or too subtle to immediately notice"

Music also can share much of the familiar territory of twelve tone music and yet have xenharmonic features. As examples, Easely Blackwood, author of "The Structure of Recognizable Diatonic Tunings", wrote many etudes in ETs from 12 equal to 24 equal which bring out both many connections and resemblances to twelve tone music as well as bringing out various xenharmonic characteristics of the tunings. See his Twelve Microtonal Etudes for Electronic Music Media.

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