thirteenth

Compound interval of a major thirteenth from F to D in the next octave up

Minor thirteenth: F to Db

In music or music theory, a thirteenth is the interval between the sixth and first scale degrees when the sixth is transposed up an octave, creating a compound sixth, or thirteenth. The thirteenth (an octave plus a sixth) is most commonly major Play (help·info) or minor Play (help·info).

A thirteenth chord is the stacking of six thirds, the last being above the 11th of an eleventh chord^[1]. Thus a thirteenth chord is a tertian (built from thirds) chord containing the interval of a thirteenth, and is an extended chord if it includes the ninth and/or the eleventh. "The jazzy thirteenth is a very versatile chord and is used in many genres."^[2] Since 13th chords tend to become unclear or confused with other chords when inverted they are generally found in root position.^[3] For example, depending on voicing, a major triad with an added major sixth is usually called a sixth chord Play (help·info), because the sixth serves as a substitution for the major seventh, thus considered a chord tone in such context. However, Walter Piston, writing in 1952, considered that, "a true thirteenth chord, arrived at by superposition of thirds, is a rare phenomenon even in 20th-century music."^[4] This may be due to four part writing, instrument limitations, and voice leading and stylistic considerations. For example, "to make the chord more playable [on guitar], thirteenth chords often omit the fifth and the ninth."^[5]

Dominant thirteenth chord in four-part writing^[3]

Most commonly 13th chords serve a dominant function (V13)^[6], whether they have the exact intervals of a dominant thirteenth or not. Typically, a dominant chord anticipating a major resolution will feature a natural 13, while a dominant chord anticipating a minor resolution will feature a flat 13^[3]. Since eleventh chords contain more than four notes, in four-voice writing the root, third, seventh, and thirteenth are most often included^[3], excluding the fifth, ninth, and eleventh Play (help·info). The third indicates the quality of the chord as major or minor, the seventh is important for the quality as a dominant chord, while the thirteenth is necessary in a thirteenth chord.

Dominant thirteenth chord in Claude Debussy's Prelude to the Afternoon of a Faun. (1894)^[7] Play (help·info)

Voice leading for dominant thirteenth chords in the common practice period.^[8] Play (help·info)

In the common practice period the "most common" pitches present in V¹³ chord are the root, 3rd, 7th, and 13th; with the 5th, 9th, and 11th "typically omitted".^[8] The 13th is most often in the soprano, or highest voice, and usually resolves down by a 3rd to the tonic I or i. If the V¹³ is followed by a I⁹ the 13th may resolve to the 9th.^[8]

These voice leading guidelines may not be followed after the common practice period in techniques such as parallel harmony and in the following example:

Alternating (♮)13 and ♭13 chords in the "railroad sonority" from mm.1-4 of All Points West (1937) by Rodgers & Hart^[9]. Play (help·info)

13th chords may less often be built on degrees other than the dominant, such as the tonic or subdominant^[6].

Lennie Tristano's ending to "I Found a New Baby" (recorded 1946) is a "tonic thirteenth chord"^[10] in lydian. Play (help·info)

In modern pop/jazz harmony, a thirteenth chord (usually notated as X13, e.g. C13) contains an implied flatted seventh interval. Thus, a C13 consists of C E G B♭ and A. The underlying harmony during a thirteenth chord is usually Mixolydian or Lydian Dominant. A thirteenth chord does not imply the quality of the ninth or eleventh scale degrees. In general, what gives a thirteenth chord its characteristic sound is the dissonance between the flat seventh and the thirteenth, a major seventh.

While the dominant thirteenth is the most common thirteenth chord, the major thirteenth is also fairly common^[11]. A major thirteenth chord (containing a major seventh) will nearly always feature a chromatically raised eleventh (C E G B D F♯ A) (see lydian mode), except for cases when the eleventh is omitted altogether. "It is customary to omit the eleventh on dominant or major thirteenth chords because the eleventh conflicts with the third,"^[11] in these chords by a semitone.

The cadence in measures 5-8 of "Noreen's Nocture" by Oscar Peterson (transcribed by Brent Edstrom) features 13th chords and also reveals the distinction between the compound and simple intervals of a 13th and an added 6th, respectively.^[8] Play (help·info)

Given the number of notes that may be included there are a great variety of thirteenth chords. The following chords are notated below lead sheet symbols:

Thirteenth chord based on minor triad[12] Play (help·info)	Thirteenth chord with flat ninth[12] Play (help·info)	[13] Play (help·info)	[13] Play (help·info)
[13] Play (help·info)	[13] Play (help·info)	[13] Play (help·info)	[13] Play (help·info)
[13] Play (help·info)	[13] Play (help·info)	[13] Play (help·info)	[13] Play (help·info)
[14] Play (help·info)	Bass note: C or alternatively G.[15] Play (help·info)	"Thirteenth chord inversion with no fifth or ninth and the flatted seventh in the bass."[16][17] Play (help·info)	Different voicing for guitar.[18] Play (help·info)

Debussy's Pelléas et Mélisande motif, at Mélisande's entrance and later when Golaud asks if she ever loved Pelléas, features, in addition to the already usual ninth, a thirteenth inverted to a "warm" close-position fourth.^[19] Play (help·info)

A non-functional example: transitional thirteenth chord from Music in Twelve Parts by Philip Glass^[20] Play (help·info)

See also

• Upper structure triad
• Jazz chord
• Harmonic planing
• Ladder of thirds

Sources

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