Triad (music)

From Wikipedia, the free encyclopedia

In music and music theory, a triad is a three-note chord (or, more generally, any set of three notes, pitches, or tones). Because the term originated during the "common practice" period in Western European art music (approximately from 1600 to 1900), it is most commonly associated with tertian diatonic chords having a tonal function^[1]. When such a chord is voiced in thirds, its members, ascending from lowest pitched tone to highest, are called:

Its members, ascending from lowest pitched note to highest, are called:

the Root
the Third (whose interval is a major third or minor third above the root)
and the Fifth (whose interval is a major or minor third above the third, and a diminished, perfect, or augmented fifth above the root).

The function of a given triad is determined primarily by its root tone and the degree of the scale to which it corresponds, and secondarily by the quality: major, minor, diminished or augmented. All but the augmented triad can be derived from the Major (or diatonic) scale. Triads (and all other larger tertian chords) are built by combining or stacking every other note. For example, C-E-G spells a triad by skipping over D and F. The four triads are built of the following intervals:

Major triads contain a major third and perfect fifth interval, symbolized: R 3 5 (or 0-4-7 as semitones)
minor triads contain a minor third, and perfect fifth, symbolized: R ♭3 5 (or 0-3-7)
diminished triads contain a minor third, and diminished fifth, symbolized: R ♭3 ♭5 (or 0-3-6)
augmented triads contain a major third, and augmented fifth, symbolized: R 3 #5 (or 0-4-8)

Primary triads of a diatonic key (major or minor) include the tonic, subdominant, and dominant degree chords, otherwise symbolized: I, IV, and V respectively.

In the twentieth century, the term triad was broadened (by Howard Hanson, for example, in his Harmonic Materials of Modern Music: Resources of the Tempered Scale^[2], by Carleton Gamer in his "Some Combinational Resources of Equal-Tempered Systems"^[3] and by others) to include three-note chords made of intervals other than thirds. We can speak thus of quartal triads, secundal triads, and so on.

[edit] Links

[edit] References

^ "Triad", Merriam-Webster. 2.
^ Hanson, H (1960) Harmonic Materials of Modern Music, Irvington, ISBN: 978-0891972075
^ Gamer, C (1967) Some Combinational Resources of Equal-Tempered Systems, Journal of Music Theory, Vol. 11, No. 1 (Spring, 1967), pp. 32-59

v • d • e Pitch sets by cardinality

Monad • Dyad • Triad • Tetrad

v • d • e Chords


By Type	Triad	Major · Minor · Augmented · Diminished · Suspended

	Seventh	Major · Minor · Dominant · Diminished · Half-diminished · Minor-major · Augmented major · Augmented minor

	Extended	Ninth · Eleventh · Thirteenth

	Other	Sixth · Augmented sixth · Altered · Added tone · Polychord · Quartal and quintal · Tone cluster · Power

By Function	Diatonic	Tonic · Dominant · Subdominant · Submediant

	Altered	Borrowed · Neapolitan chord · Secondary dominant

With Names		Elektra chord · Hendrix chord · Mystic chord · Petrushka chord · Tristan chord · So What chord