"Tertial" redirects here. For the feathers in a bird's wing see tertials.

In music theory

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...

, tertian (Latin: tertianus, "of or concerning thirds") describes any piece, chord

Chord (music)

A chord in music is any harmonic set of two–three or more notes that is heard as if sounding simultaneously. These need not actually be played together: arpeggios and broken chords may for many practical and theoretical purposes be understood as chords...

, counterpoint

Counterpoint

In music, counterpoint is the relationship between two or more voices that are independent in contour and rhythm and are harmonically interdependent . It has been most commonly identified in classical music, developing strongly during the Renaissance and in much of the common practice period,...

 etc. constructed from the interval

Interval (music)

In music theory, an interval is a combination of two notes, or the ratio between their frequencies. Two-note combinations are also called dyads...

 of a third

Third (music)

In music and music theory third may refer to:*major third*minor third*augmented third/perfect fourth*diminished third/major second*Third , chord member a third above the root*Mediant, third degree of the diatonic scale...

. An interval such as that between the notes A and C encompasses 3 semitone

Semitone

A semitone, also called a 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....

 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 major third (See Major and minor

Major and minor

In Western music, the adjectives major and minor can describe a musical composition, movement, section, scale, key, chord, or interval.Major and minor are frequently referred to in the titles of classical compositions, especially in reference to the key of a piece.-Intervals and chords:With regard...

).
A common 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...

 chord can be regarded as consisting of a "stack" of two such intervals. A musical scale may also be analysed as a succession of thirds (See Ladder of thirds

Ladder of thirds

A ladder of thirds is similar to the circle of fifths, though a ladder of thirds differs in being composed of thirds, major or minor, and may or may not circle back to its starting note and thus may or may not be an interval cycle.Triadic chords may be considered as part of a ladder of thirds.It...

). The meantone temperament

Meantone temperament

Meantone temperament is a musical temperament, which is a system of musical tuning. In general, a meantone is constructed the same way as Pythagorean tuning, as a stack of perfect fifths, but in meantone, each fifth is narrow compared to the ratio 27/12:1 in 12 equal temperament, the opposite of...

, a system of tuning that emphasises pure thirds, may be called "tertian".

Chords built from sixth

Sixth

Sixth can refer to:* The ordinal form of the number six* Sixth Amendment to the U.S. Constitution* A keg of beer equal to 5 U.S. gallons or 1/6 barrel of beer.* A fraction, such as 1/6-Music:*Interval*Major sixth*Minor sixth...

s may also be referred to as tertian because an ascending sixth is equal to a descending third and vice versa: any sixth can be taken as the inversion

Inversion (music)

In music theory, the word inversion has several meanings. There are inverted chords, inverted melodies, inverted intervals, and inverted voices...

 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 concepts have been used innovatively in chord progression

Chord progression

A chord progression is a series of musical chords, or chord changes that "aims for a definite goal" of establishing a tonality founded on a key, root or tonic chord. In other words, the succession of root relationships...

s, as for example in the "thirds cycle" used in John Coltrane' Coltrane changes

Coltrane changes

In jazz harmony, the Coltrane changes are a harmonic progression variation using substitute chords over common jazz chord progressions...

.