Seventh chord

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A seventh chord is a chord consisting of a triad plus a note forming an interval of a seventh above the chord's root. When not otherwise specified, a "seventh chord" usually means a dominant seventh chord: a major triad together with a minor seventh. However, a variety of sevenths may be added to a variety of triads, resulting in many different types of seventh chords.

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In its earliest usage, the seventh was introduced solely as an embellishing or nonchord tone. The seventh destabilized the triad, and allowed the composer to emphasize movement in a given direction. As time passed and the collective ear of the western world became more accustomed to dissonance, the seventh was allowed to become a part of the chord itself, and in some modern music, jazz in particular, nearly every chord is a seventh chord[ vague ]. Additionally, the general acceptance of equal temperament during the 19th century reduced the dissonance of some earlier forms of sevenths.

"A ranking by frequency of the seventh chords in C major would be approximately that shown."
Play V (Dominant), ii (Minor), vii (Half-diminished), IVM (Major), vi, IM, or iii Seventh chords frequency.png
"A ranking by frequency of the seventh chords in C major would be approximately that shown."
Play V (Dominant), ii (Minor), vii (Half-diminished), IVM (Major), vi , IM , or iii

Classification

Most textbooks name these chords formally by the type of triad and type of seventh; hence, a chord consisting of a major triad and a minor seventh above the root is referred to as a major/minor seventh chord. When the triad type and seventh type are identical (i.e. they are both major, minor, or diminished), the name is shortened. For instance, a major/major seventh is generally referred to as a major seventh. This rule is not valid for augmented chords: since the augmented/augmented chord is not commonly used, the abbreviation augmented is used for augmented/minor, rather than augmented/augmented. Additionally, half-diminished stands for diminished/minor, and dominant stands for major/minor. When the type is not specified at all, the triad is assumed to be major, and the seventh is understood as a minor seventh (e.g. a "C" chord is a "C major triad", and a "C7" chord is a "C major/minor seventh chord", also known as a "C dominant seventh chord"). For symbols used for seventh chords, see also Popular music symbols § Seventh chords.

Tertian

The most common chords are tertian, constructed using a sequence of major thirds (spanning 4 semitones) and/or minor thirds (3 semitones). Since there are 3 third intervals in a seventh chord (4 notes) and each can be major or minor, there are 7 possible permutations (the 8th one, consisted of four major thirds, results in a non-seventh augmented chord, since a major third equally divides the octave [2] ). The five commonly found in western music are the major seventh, the minor (or minor/minor) seventh, the dominant (or major/minor) seventh, the half-diminished seventh, and the diminished seventh. The less commonly found tertians are the minor major seventh and the augmented major seventh.

Tertian seventh chords used in Western music
Common nameChord on CCommon symbols
on C
Intervals from root Quality of consecutive thirds
ThirdFifthSeventh1st2nd3rd
Major seventh
Seventh chord
Cmaj7
CM7
CΔ7
CΔ
major perfect major majorminormajor
Minor seventh
Seventh chord
Cmin7
Cm7
C−7
minor perfect minor minormajorminor
Dominant seventh
Seventh chord
C7majorperfectminormajorminorminor
Half-diminished seventh
Seventh chord
Cm75
C−75
Cø7
minordiminishedminorminorminormajor
Diminished seventh
Seventh chord
Co7
Cdim7
Cm(7)5
C−(7)5
minor diminished diminished minorminorminor
Minor major seventh
Seventh chord
Cmmaj7
CmM7
CmΔ7
C−Δ7
minorperfectmajorminormajormajor
Augmented major seventh
Seventh chord
Caugmaj7
C+maj7
C+M7
C+Δ7
major augmented majormajormajorminor

Non-tertian

Seventh chords can also be constructed using augmented or diminished thirds. These chords are not tertian and can be used in non-tertian harmony. There are many (mathematically, 64) chords that can be built, however, only a few of them are used in Western music.

Commonly used non-tertian seventh chords
Common nameChord on CCommon symbols
on C
Intervals from root Quality of consecutive thirds
ThirdFifthSeventh1st2nd3rd
Augmented seventh
Seventh chord
Caug7
C+7
majoraugmentedminormajormajor diminished
(equiv. major second)
Diminished major seventh
Seventh chord
CmM75
C−Δ75
minordiminishedmajorminorminor augmented
(equiv. perfect fourth)
Dominant seventh flat five
Seventh chord
C75majordiminishedminormajordiminishedmajor
Major seventh flat five
Seventh chord
CM75majordiminishedmajormajordiminishedaugmented


In tuning systems other than equal temperament there are further possible seventh chords. In just intonation, for example, there is the harmonic seventh.

Types

Dominant seventh chord

Seventh chord
The dominant seventh chord (V7) in C major, G7

A dominant seventh chord, or major-minor seventh chord is a chord composed of a root, major third, perfect fifth, and minor seventh. It can be also viewed as a major triad with an additional minor seventh. It is denoted using popular music symbols by adding a superscript "7" after the letter designating the chord root. [3] :77 The dominant seventh is found almost as often as the dominant triad. [3] :199 The chord can be represented by the integer notation (0, 4, 7, 10).

Of all the seventh chords, perhaps the most important is the dominant seventh. It was the first seventh chord to appear regularly in classical music. The name comes from the fact that the flat seventh occurs naturally in the scale built upon the root when it functions as the dominant (i.e., the fifth degree) of some major diatonic scale.

Take for example the C major scale (C, D, E, F, G, A, B, C):

Seventh chord

The note G is the dominant degree of C major—its fifth note. When we arrange the notes of the C major scale in ascending pitch and use only these notes to build a seventh chord, and we start with G (not C), then the resulting chord contains the four notes G–B–D–F and is called G dominant seventh (G7). The note F is a minor seventh from G, and is also called the dominant seventh with respect to G.

Harmonic seventh chord

Seventh chord
The harmonic seventh chord on C

The harmonic seventh chord is a dominant seventh chord formed by a major triad plus a harmonic seventh interval.

The harmonic seventh interval is a minor seventh tuned in the 7:4 pitch ratio, one of the possible "just ratios" defined for this interval in just intonation (slightly below the width of a minor seventh as tuned in equal temperament). With just intonation on all notes of the harmonic seventh chord, the ratio between the frequencies of the pitches in the chord is 4:5:6:7. For example, a justly intuned A harmonic seventh chord in root position starting at A440 consists of the pitches 440 Hz, 550 Hz, 660 Hz, and 770 Hz.

Sometimes called a "blue note", the harmonic seventh is used by singers, through note bending on guitars, and on other instruments not restricted to equal temperament. An often heard example of the harmonic seventh chord is the last word of the modern addition to the song "Happy Birthday to You", with the lyrics, "and many more!" The harmony on the word "more" is typically sung as a harmonic seventh chord. [4]

Frequent use of the harmonic seventh chord is one of the defining characteristics of blues and barbershop harmony; barbershoppers refer to it as "the barbershop seventh". Since barbershop music tends to be sung in just intonation, the barbershop seventh chord may be accurately termed a harmonic seventh chord. The harmonic seventh chord is also widely used in blues-flavored music. As pianos, and other equal-temperament instruments cannot play this chord, it is frequently approximated by a dominant seventh. As a result, it is often called a dominant seventh chord and written with the same symbols (such as the blues progression I7–V7–IV7).

Major and minor seventh chords

Seventh chord
The minor seventh chord (ii7) in C major, D–7

While the dominant seventh chord is typically built on the fifth (or dominant) degree of a major scale, the minor seventh chord is built on the second, third, or sixth degree. A minor seventh chord contains the same notes as an added sixth chord. For example, C–E–G–B can function as both a C minor seventh and an E added sixth (Id chord).

Seventh chord
The major seventh chord (IV7) in C major, FΔ7

Major seventh chords are usually constructed on the first or fourth degree of a scale, (in C or G major: C–E–G–B). Due to the major seventh interval between the root and seventh (C–B, an inverted minor second), this chord can sometimes sound dissonant, depending on the voicing used. For example, Bacharach and David's "Raindrops Keep Fallin' on My Head" opens with a major chord followed by a major seventh in the next measure.

The major seventh is sometimes notated as Δ7 (a delta chord) or just a Δ (which has the same meaning).

Half-diminished seventh chord

Seventh chord
The leading-tone seventh chord (viiø7) in C major, Bø7

A half-diminished seventh chord is a seventh chord built from the seventh degree of a major scale. It is considered "half-diminished" because a fully diminished seventh has a double-flatted (diminished) seventh, making it enharmonically the same as a major sixth. The half-diminished seventh chord uses a minor seventh over the root of a diminished triad.

Example: (in the key of C major) B–D–F–A.

Diminished seventh chord

Seventh chord
The diminished seventh chord on B

A diminished seventh chord is made of three superimposed minor thirds (e.g., B–D–F–A), which is two tritones a minor third apart (e.g., B–F, D–A). The diminished seventh chord has been used by composers and musicians for a variety of reasons over time. Some reasons include: as a symbol of Sturm und Drang; modulation; and for characterisation. The diminished seventh chord is seen more frequently in late classical and romantic period works but is also found in Baroque and Renaissance period works, though not as frequently.

All of the elements of the diminished seventh chord can be found in the dominant seventh flat nine (79) chord as seen in a comparison of the two chords.

Inversions

Seventh chord

There are four different inversions of a seventh chord. Following basso continuo notation, the inversions are as follows:

Additional numbers are used to indicate the seventh chords and their inversions. [5]

See also

Related Research Articles

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<span class="mw-page-title-main">Perfect fifth</span> Musical interval

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<span class="mw-page-title-main">Chord (music)</span> Harmonic set of three or more notes

In music, a chord is a group of three or more notes played simultaneously, typically consisting of a root note, a third, and a fifth. Chords are the building blocks of harmony and form the harmonic foundation of a piece of music. They can be major, minor, diminished, augmented, or extended, depending on the intervals between the notes and their arrangement. Chords provide the harmonic support and coloration that accompany melodies and contribute to the overall sound and mood of a musical composition. For many practical and theoretical purposes, arpeggios and other types of broken chords may also be considered as chords in the right musical context.

<span class="mw-page-title-main">Major third</span> Musical interval

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<span class="mw-page-title-main">Major sixth</span> Musical interval

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<span class="mw-page-title-main">Major chord</span> Chord having a root, a major third, and a perfect fifth

In music theory, a major chord is a chord that has a root, a major third, and a perfect fifth. When a chord comprises only these three notes, it is called a major triad. For example, the major triad built on C, called a C major triad, has pitches C–E–G:

<span class="mw-page-title-main">Augmented fifth</span> Musical interval

In Western classical music, an augmented fifth is an interval produced by widening a perfect fifth by a chromatic semitone. For instance, the interval from C to G is a perfect fifth, seven semitones wide, and both the intervals from C to G, and from C to G are augmented fifths, spanning eight semitones. Being augmented, it is considered a dissonant interval.

In music theory, an augmented sixth chord contains the interval of an augmented sixth, usually above its bass tone. This chord has its origins in the Renaissance, was further developed in the Baroque, and became a distinctive part of the musical style of the Classical and Romantic periods.

In music, a triad is a set of three notes that can be stacked vertically in thirds. Triads are the most common chords in Western music.

In music theory, a dominant seventh chord, or major minor seventh chord, is a seventh chord, composed of a root, major third, perfect fifth, and minor seventh. Thus it is a major triad together with a minor seventh, denoted by the letter name of the chord root and a superscript "7". In most cases, dominant seventh chord are built on the fifth degree of the major scale. An example is the dominant seventh chord built on G, written as G7, having pitches G–B–D–F:

In Western music, the adjectives major and minor may describe an interval, chord, scale, or key. A composition, movement, section, or phrase may also be referred to by its key, including whether that key is major or minor.

<span class="mw-page-title-main">Guitar chord</span> Set of notes played on a guitar

In music, a guitar chord is a set of notes played on a guitar. A chord's notes are often played simultaneously, but they can be played sequentially in an arpeggio. The implementation of guitar chords depends on the guitar tuning. Most guitars used in popular music have six strings with the "standard" tuning of the Spanish classical guitar, namely E–A–D–G–B–E' ; in standard tuning, the intervals present among adjacent strings are perfect fourths except for the major third (G,B). Standard tuning requires four chord-shapes for the major triads.

<span class="mw-page-title-main">Harmonic major scale</span> Musical scale

In music theory, the harmonic major scale is a musical scale found in some music from the common practice era and now used occasionally, most often in jazz. In George Russell's Lydian Chromatic Concept it is the fifth mode (V) of the Lydian Diminished scale. It corresponds to the Raga Sarasangi in Indian Carnatic music, or Raag Nat Bhairav in Hindustani music.

In music, septimal meantone temperament, also called standard septimal meantone or simply septimal meantone, refers to the tempering of 7-limit musical intervals by a meantone temperament tuning in the range from fifths flattened by the amount of fifths for 12 equal temperament to those as flat as 19 equal temperament, with 31 equal temperament being a more or less optimal tuning for both the 5- and 7-limits.

The harmonic minor scale is a musical scale derived from the natural minor scale, with the minor seventh degree raised by one semitone to a major seventh, creating an augmented second between the sixth and seventh degrees.

<span class="mw-page-title-main">Harmonic seventh</span> Musical interval

The harmonic seventh interval, also known as the septimal minor seventh, or subminor seventh, is one with an exact 7:4 ratio (about 969 cents). This is somewhat narrower than and is, "particularly sweet", "sweeter in quality" than an "ordinary" just minor seventh, which has an intonation ratio of 9:5 (about 1018 cents).

<span class="mw-page-title-main">Harmonic seventh chord</span> A major triad plus the harmonic seventh interval

The harmonic seventh chord is a major triad plus the harmonic seventh interval. This interval is somewhat narrower and is "sweeter in quality" than an "ordinary" minor seventh, which has a just intonation ratio of 9:5, or an equal-temperament ratio of 1000 cents.

Musicians use various kinds of chord names and symbols in different contexts to represent musical chords. In most genres of popular music, including jazz, pop, and rock, a chord name and its corresponding symbol typically indicate one or more of the following:

  1. the root note,
  2. the chord quality,
  3. whether the chord is a triad, seventh chord, or an extended chord,
  4. any altered notes,
  5. any added tones, and
  6. the bass note if it is not the root.

References

  1. Kostka; Payne (1995). Tonal Harmony (3rd ed.). p. 225. ISBN   0-07-300056-6.
  2. Hughes, Bryn. "Equal Divisions of the Octave". Open Music Theory. University of Nebraska System.
  3. 1 2 Benward; Saker (2003). Music: In Theory and Practice, Vol. I (7th ed.). ISBN   978-0-07-294262-0.
  4. Mathieu, W. A. (1997). Harmonic Experience. Rochester, Vermont: Inner Traditions International. p.  126. ISBN   0-89281-560-4.
  5. Seventh chord - Inversions - HK Piano