music theory Music theory is the study of theoretical frameworks for understanding the practices and possibilities of music. ''The Oxford Companion to Music'' describes three interrelated uses of the term "music theory": The first is the "Elements of music, ...

, ''tertian'' (, "of or concerning thirds") describes any piece, chord,

counterpoint In music theory, counterpoint is the relationship of two or more simultaneous musical lines (also called voices) that are harmonically dependent on each other, yet independent in rhythm and melodic contour. The term originates from the Latin ...

etc. constructed from the intervals of (

major Major most commonly refers to: * Major (rank), a military rank * Academic major, an academic discipline to which an undergraduate student formally commits * People named Major, including given names, surnames, nicknames * Major and minor in musi ...

and minor) thirds. An interval such as that between the notes A and C encompasses 3

semitone A semitone, also called a minor second, half step, or a half tone, is the smallest musical interval commonly used in Western tonal music, and it is considered the most dissonant when sounded harmonically. It is defined as the interval between ...

intervals (A-B-B-C) and is termed a minor third while one such as that between C and E encompasses 4 semitones (C-D-D-E-E) and is called a

third. Tertian harmony (also called tertiary harmony ) principally uses chords based on thirds; the term is typically used to contrast with quartal and quintal harmony which uses chords based on fourths or fifths. A common triad chord can be regarded as consisting of a "stack" of two consecutive thirds. This allows for four permutations, each producing a chord with distinct

quality Quality may refer to: Concepts *Quality (business), the ''non-inferiority'' or ''superiority'' of something *Quality (philosophy), an attribute or a property *Quality (physics), in response theory *Energy quality, used in various science discipli ...

: A musical scale may also be analyzed as a succession of thirds. The

meantone temperament Meantone temperaments are musical temperaments; that is, a variety of Musical tuning#Tuning systems, tuning systems constructed, similarly to Pythagorean tuning, as a sequence of equal fifths, both rising and descending, scaled to remain within th ...

, a system of tuning that emphasizes pure thirds, may be called "tertian". Chords built from sixths may also be referred to as tertian because sixths are equivalent to thirds when inverted, and vice versa: any sixth can be taken as the inversion of a third. For instance, the interval C-A is a major sixth that, when inverted, gives the interval A-C, which is a minor third. Tertian root movements have been used innovatively in

chord progression In a musical composition, a chord progression or harmonic progression (informally chord changes, used as a plural, or simply changes) is a succession of chords. Chord progressions are the foundation of harmony in Western musical tradition from ...

s as an alternative to root motion in fifths, as for example in the "thirds cycle" used in John Coltrane's Coltrane changes, as influenced by Nicolas Slonimsky's ''Thesaurus of Scales and Melodic Patterns''.

References

{{Chords Chords Thirds (music)

See also

References