Trichord
Encyclopedia
In music theory
, a trichord is a group of three different pitch classes found within a larger group (Friedmann 1990, 42). For example a continguous three note set
from a musical scale (Houlahan & Tacka 2008, 54) or twelve-tone row. The term is derived by analogy from the 20th-century use of the word "tetrachord
". Unlike the tetrachord and hexachord
, there is no traditional standard scale arrangement of three notes, nor is the trichord necessarily thought of as a harmonic entity (Rushton 2001).
Just as a diatonic scale is conventionally said to be constructed of two disjunct tetrachords (CDEF+GABC=CDEFGABC), a pentatonic scale
can be constructed of two disjunct trichords (ACD+EGA=ACDEGA; GAC+DEG=GACDEG).
Milton Babbitt
's serial theory of combinatoriality makes much of the properties of three-note, four-note, and six-note segments of a twelve-tone row, which he calls, respectively, trichords, tetrachords, and hexachords, extending the traditional sense of the terms and retaining their implication of contiguity (Babbitt 2003, 59).
Allen Forte occasionally makes informal use of the term trichord (Forte 1973, 124 and 126) to mean what he usually calls "sets of three elements" (Forte 1973, 3, 23, 27, and 47), and other theorists (notably including Hanson
1960, and Gamer
1967, 37, 46, 50–52), mean by the term triad
, a three-note pitch collection which is not necessarily a contiguous segment of a scale or a tone row and not necessarily (in twentieth-century music) tertian or diatonic either.
Music theory
Music theory is the study of how music works. It examines the language and notation of music. It seeks to identify patterns and structures in composers' techniques across or within genres, styles, or historical periods...
, a trichord is a group of three different pitch classes found within a larger group (Friedmann 1990, 42). For example a continguous three note set
Set (music)
A set in music theory, as in mathematics and general parlance, is a collection of objects...
from a musical scale (Houlahan & Tacka 2008, 54) or twelve-tone row. The term is derived by analogy from the 20th-century use of the word "tetrachord
Tetrachord
Traditionally, a tetrachord is a series of three intervals filling in the interval of a perfect fourth, a 4:3 frequency proportion. In modern usage a tetrachord is any four-note segment of a scale or tone row. The term tetrachord derives from ancient Greek music theory...
". Unlike the tetrachord and hexachord
Hexachord
In music, a hexachord is a collection of six pitch classes including six-note segments of a scale or tone row. The term was adopted in the Middle Ages and adapted in the twentieth-century in Milton Babbitt's serial theory.-Middle Ages:...
, there is no traditional standard scale arrangement of three notes, nor is the trichord necessarily thought of as a harmonic entity (Rushton 2001).
Just as a diatonic scale is conventionally said to be constructed of two disjunct tetrachords (CDEF+GABC=CDEFGABC), a pentatonic scale
Pentatonic scale
A pentatonic scale is a musical scale with five notes per octave in contrast to a heptatonic scale such as the major scale and minor scale...
can be constructed of two disjunct trichords (ACD+EGA=ACDEGA; GAC+DEG=GACDEG).
Milton Babbitt
Milton Babbitt
Milton Byron Babbitt was an American composer, music theorist, and teacher. He is particularly noted for his serial and electronic music.-Biography:...
's serial theory of combinatoriality makes much of the properties of three-note, four-note, and six-note segments of a twelve-tone row, which he calls, respectively, trichords, tetrachords, and hexachords, extending the traditional sense of the terms and retaining their implication of contiguity (Babbitt 2003, 59).
Allen Forte occasionally makes informal use of the term trichord (Forte 1973, 124 and 126) to mean what he usually calls "sets of three elements" (Forte 1973, 3, 23, 27, and 47), and other theorists (notably including Hanson
Howard Hanson
Howard Harold Hanson was an American composer, conductor, educator, music theorist, and champion of American classical music. As director for 40 years of the Eastman School of Music, he built a high-quality school and provided opportunities for commissioning and performing American music...
1960, and Gamer
Carlton Gamer
Carlton Gamer is an American composer and music theorist. He has taught at Princeton University, the University of Michigan, and Colorado College...
1967, 37, 46, 50–52), mean by the term triad
Triad (music)
In music and music theory, a triad is a three-note chord that can be stacked in thirds. Its members, when actually stacked in thirds, from lowest pitched tone to highest, are called:* the Root...
, a three-note pitch collection which is not necessarily a contiguous segment of a scale or a tone row and not necessarily (in twentieth-century music) tertian or diatonic either.
Further reading
- Gilbert, Steven E. (1970). "The Trichord: An Analytic Outlook for Twentieth-Century Music". Ph.D. diss. New Haven: Yale University.