View source for Seventh chord

{{Short description|Musical chord}}
{{More citations needed|date=November 2012}}
{{Image frame|content=<score lang="lilypond">
{
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\relative c' { 
  \clef treble 
  \time 4/4
  <c e g bes>1
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</score>|width=120|caption=The [[dominant seventh chord]] on C}}
A '''seventh chord''' is a [[chord (music)|chord]] consisting of a [[triad (music)|triad]] plus a note forming an [[interval (music)|interval]] of a [[Interval (music)|seventh]] above the chord's [[root (chord)|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.

In its earliest usage, the seventh was introduced solely as an [[nonchord tone|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 [[Consonance and dissonance|dissonance]], the seventh was allowed to become a part of the chord itself, and in some modern music, jazz in particular, {{Vague|date=May 2024|text=nearly every chord is a seventh chord|reason=what is this claim based on?}}. Additionally, the general acceptance of [[equal temperament]] during the 19th century reduced the dissonance of some earlier forms of sevenths.

[[File:Seventh chords frequency.png|thumb|center|400px|"A ranking by frequency of the seventh chords in C major would be approximately that shown."<ref>{{cite book|last1=Kostka|last2=Payne|date=1995|title=Tonal Harmony|page=225|edition=3rd|isbn=0-07-300056-6}}</ref>
<br />{{audio|Dominant seventh chord V7 in C.mid|Play V<sup>7</sup>}} ([[#Dominant seventh chord|Dominant]]), {{audio|Minor seventh chord on d ii7 in C.mid|ii<sup>7</sup>}} ([[#Major and minor seventh chords|Minor]]), {{audio|Leading-tone seventh chord in C major.mid|vii{{music|halfdim}}<sup>7</sup>}} ([[#Half-diminished seventh chord|Half-diminished]]), {{audio|Major seventh chord on F.mid|IVM<sup>7</sup>}} ([[#Major and minor seventh chords|Major]]), {{audio|Minor seventh chord on a vi7 in C.mid|vi<sup>7</sup>}}, {{audio|Major seventh chord on C.mid|IM<sup>7</sup>}}, or {{audio|Minor seventh chord on e iii7 in C.mid|iii<sup>7</sup>}}]]

== 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 "C<sup>7</sup>" chord is a "[[Dominant seventh chord|C major/minor seventh chord]]", also known as a "C dominant seventh chord"). For symbols used for seventh chords, see also {{slink|Popular music symbols|Seventh chords}}.

=== Tertian ===

The most common chords are [[tertian]], constructed using a sequence of [[major third]]s (spanning 4 [[semitone]]s) and/or [[minor third]]s (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<ref>{{cite journal|url=https://pressbooks.nebraska.edu/openmusictheory/chapter/equal-divisions-of-the-octave/|title=Equal Divisions of the Octave|last=Hughes|first=Bryn|website=Open Music Theory|date=July 2021 |publisher=University of Nebraska System}}</ref>). 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.

{|class="wikitable" style="text-align:center;"
|+Tertian seventh chords used in Western music
|-
!rowspan="2"|Common name !! rowspan="2"|Chord on C !! rowspan="2"|Common symbols<br />on C !! colspan="3"|Intervals from root !! colspan="3"|[[Interval (music)#Quality|Quality]] of consecutive thirds
|-
!Third!!Fifth!!Seventh !! 1st!!2nd!!3rd
|-
|[[Major seventh chord|Major seventh]] ||<score lang="lilypond"> {
\override Score.TimeSignature #'stencil = ##f
\relative c' { 
  \clef treble \time 4/4
  <c e g b>1
} }
</score>
| Cmaj<sup>7</sup><br />CM<sup>7</sup><br />C<sup>{{music|major}}7</sup><br />C<sup>{{music|major}}</sup> || [[major third|major]] || [[perfect fifth|perfect]] || [[major seventh|major]] || major || minor|| major
|-
|[[Minor seventh chord|Minor seventh]] ||<score lang="lilypond"> {
\override Score.TimeSignature #'stencil = ##f
\relative c' { 
  \clef treble \time 4/4
  <c es g bes>1
} }
</score>
| Cmin<sup>7</sup><br />Cm<sup>7</sup><br />C−<sup>7</sup> || [[minor third|minor]] || perfect || [[minor seventh|minor]] || minor || major || minor
|-
|[[Dominant seventh chord|Dominant seventh]] ||<score lang="lilypond"> {
\override Score.TimeSignature #'stencil = ##f
\relative c' { 
  \clef treble \time 4/4
  <c e g bes>1
} }
</score>
| C<sup>7</sup> || major || perfect || minor || major || minor || minor
|-
|[[Half-diminished seventh chord|Half-diminished seventh]] ||<score lang="lilypond"> {
\override Score.TimeSignature #'stencil = ##f
\relative c' { 
  \clef treble \time 4/4
  <c es ges bes>1
} }
</score>
| Cm<sup>7{{music|b}}5</sup><br />C−<sup>7{{music|b}}5</sup><br />C{{music|halfdim}}<sup>7</sup> || minor || diminished || minor || minor || minor || major
|-
|[[Diminished seventh chord|Diminished seventh]] ||<score lang="lilypond"> {
\override Score.TimeSignature #'stencil = ##f
\relative c' { 
  \clef treble \time 4/4
  <c es ges beses>1
} }
</score>
| C{{music|diminished}}<sup>7</sup><br />Cdim<sup>7</sup><br />Cm<sup>({{music|b}}7){{music|b}}5</sup><br />C−<sup>({{music|b}}7){{music|b}}5</sup>  || minor || [[diminished fifth|diminished]] || [[diminished seventh|diminished]] || minor || minor || minor
|-
|[[Minor major seventh chord|Minor major seventh]] ||<score lang="lilypond"> {
\override Score.TimeSignature #'stencil = ##f
\relative c' { 
  \clef treble \time 4/4
  <c es g b>1
} }
</score>
| Cm<sup>maj7</sup><br />Cm<sup>M7</sup><br />Cm<sup>{{music|major}}7</sup><br />C−<sup>{{music|major}}7</sup> || minor || perfect || major || minor || major || major
|-
|[[Augmented major seventh chord|Augmented major seventh]] ||<score lang="lilypond"> {
\override Score.TimeSignature #'stencil = ##f
\relative c' { 
  \clef treble \time 4/4
  <c e gis b>1
} }
</score>
| Caug<sup>maj7</sup><br />C+<sup>maj7</sup><br />C+<sup>M7</sup><br />C+<sup>{{music|major}}7</sup> || major || [[Augmented fifth|augmented]] || major || major || major || minor
|}

=== 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.

{|class="wikitable" style="text-align:center;"
|+Commonly used non-tertian seventh chords
|-
!rowspan="2"|Common name !! rowspan="2"|Chord on C !! rowspan="2"|Common symbols<br />on C !! colspan="3"|Intervals from root !! colspan="3"|[[Interval (music)#Quality|Quality]] of consecutive thirds
|-
!Third!!Fifth!!Seventh !! 1st!!2nd!!3rd
|-
|[[Augmented seventh chord|Augmented seventh]] ||<score lang="lilypond"> {
\override Score.TimeSignature #'stencil = ##f
\relative c' { 
  \clef treble \time 4/4
  <c e gis bes>1
} }
</score>
| Caug<sup>7</sup><br />C+<sup>7</sup> || major || augmented || minor || major || major || [[Diminished third|diminished]]<br />(equiv. [[major second]])
|-
|[[Diminished major seventh chord|Diminished major seventh]] ||<score lang="lilypond"> {
\override Score.TimeSignature #'stencil = ##f
\relative c' { 
  \clef treble \time 4/4
  <c es ges b>1
} }
</score>
| Cm<sup>M7{{music|b}}5</sup><br />C−<sup>{{music|major}}7{{music|b}}5</sup> || minor || diminished || major || minor || minor || [[Augmented third|augmented]]<br />(equiv. [[perfect fourth]])
|-
|[[Dominant seventh flat five chord|Dominant seventh flat five]] ||<score lang="lilypond"> {
\override Score.TimeSignature #'stencil = ##f
\relative c' { 
  \clef treble \time 4/4
  <c e ges bes>1
} }
</score>
| C<sup>7{{music|b}}5</sup> || major || diminished || minor || major || diminished || major
|-
|Major seventh flat five ||<score lang="lilypond"> {
\override Score.TimeSignature #'stencil = ##f
\relative c' { 
  \clef treble \time 4/4
  <c e ges b>1
} }
</score>|| C<sup>M7{{music|b}}5</sup> || major || diminished || major || major || diminished || augmented
|}
<br />
In tuning systems other than [[equal temperament]] there are further possible seventh chords. In [[just intonation]], for example, there is the [[Harmonic seventh chord|harmonic seventh]].

<span id="The dominant seventh"></span><!--This anchor has been added in order that change of the name of the section may not affect links. -->

== Types ==

=== Dominant seventh chord ===
{{Main|Dominant seventh chord}}{{Image frame|content=<score lang="lilypond">
{
\override Score.TimeSignature #'stencil = ##f
\relative c'' { 
  \clef treble 
  \time 4/4
  <g b d f>1
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</score>|width=120|caption=The dominant seventh chord (V<sup>7</sup>) in C major, G<sup>7</sup>}}
A dominant seventh chord, or major-minor seventh chord is a [[chord (music)|chord]] composed of a [[root (chord)|root]], [[major third]], [[perfect fifth]] -- a [[Major chord|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.<ref name="benwardsaker">{{cite book|last1=Benward|last2=Saker|date=2003|title=Music: In Theory and Practice, Vol. I|publisher=McGraw-Hill |edition=7th|isbn=978-0-07-294262-0}}</ref>{{rp|77}} The dominant seventh is found almost as often as the [[dominant (music)|dominant triad]].<ref name="benwardsaker" />{{rp|199}} The chord can be represented by the [[Pitch class#Integer notation|integer notation]] (0,&nbsp;4,&nbsp;7,&nbsp;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 (music)|dominant]] (i.e., the fifth [[Scale degree|degree]]) of some major [[diatonic scale]].

Take for example the C major scale (C, D, E, F, G, A, B, C):<blockquote><score sound="1"> {
\override Score.TimeSignature #'stencil = ##f
\relative c' { 
  \clef treble 
  \time 7/4 c4 \once \override NoteHead.color = #red d e \once \override NoteHead.color = #red f \once \override NoteHead.color = #red g a \once \override NoteHead.color = #red b \time 4/4 c1 \bar "||"
  \time 4/4 <d, f g b>2 <g b d f> \bar "||"
} }
</score></blockquote>

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 (G<sup>7</sup>). The note F is a [[minor seventh]] from G, and is also called the dominant seventh with respect to G.

=== Harmonic seventh chord ===
{{Main|Harmonic seventh chord}}
{{Image frame|content=<score sound="1" override_midi="Harmonic seventh chord on C.mid">
{
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\relative c' { 
  \clef treble 
  \time 4/4
  <c e g beseh c>1
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</score>|width=300|caption=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 [[Interval ratio|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 (pitch standard)|A440]] consists of the pitches 440&nbsp;Hz, 550&nbsp;Hz, 660&nbsp;Hz, and 770&nbsp;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.<ref name="Mathieu pg. 126">{{cite book|last=Mathieu|first=W. A.|title=Harmonic Experience|publisher=Inner Traditions International|location=Rochester, Vermont|date=1997|isbn=0-89281-560-4|page=[https://archive.org/details/harmonicexperien0000math/page/126 126]|url=https://archive.org/details/harmonicexperien0000math/page/126}}</ref>

Frequent use of the harmonic seventh chord is one of the defining characteristics of [[blues]] and [[Barbershop music|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 I<sup>7</sup>–V<sup>7</sup>–IV<sup>7</sup>).

=== Major and minor seventh chords ===
{{Main|Major seventh chord|Minor seventh chord}}{{Image frame|content=<score lang="lilypond">
{
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\relative c' { 
  \clef treble 
  \time 4/4
  <d f a c>1
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</score>|width=120|caption=The minor seventh chord (ii<sup>7</sup>) in C major, D–<sup>7</sup>}}
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 [[Sixth chord|added sixth chord]]. For example, C–E{{music|flat}}–G–B{{music|flat}} can function as both a C minor seventh and an E{{music|flat}} added sixth (Id chord).{{Image frame|content=<score lang="lilypond">
{
\override Score.TimeSignature #'stencil = ##f
\relative c' { 
  \clef treble 
  \time 4/4
  <f a c e>1
} }
</score>|width=120|align=right|caption=The major seventh chord (IV<sup>7</sup>) in C major, F{{music|major}}<sup>7</sup>}}
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, [[Burt Bacharach|Bacharach]] and [[Hal David|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 {{music|major}}7 (a delta chord) or just a {{music|delta}} (which has the same meaning).

=== Half-diminished seventh chord ===
{{Main|Half-diminished seventh chord}}{{Image frame|content=<score lang="lilypond">
{
\override Score.TimeSignature #'stencil = ##f
\relative c' { 
  \clef treble 
  \time 4/4
  <b d f a>1
} }
</score>|width=120|caption=The leading-tone seventh chord (vii{{music|halfdim}}<sup>7</sup>) in C major, B{{music|halfdim}}<sup>7</sup>}}
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 [[enharmonic]]ally 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 ===
{{Main|Diminished seventh chord}}{{Image frame|content=<score lang="lilypond">
{
\override Score.TimeSignature #'stencil = ##f
\relative c' { 
  \clef treble 
  \time 4/4
  <b d f aes>1
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</score>|width=120|caption=The diminished seventh chord on B}}A diminished seventh chord is made of three superimposed minor thirds (e.g., B–D–F–A{{music|flat}}), which is two tritones a minor third apart (e.g., B–F, D–A{{music|flat}}). 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 (music)|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 (7{{music|b}}9) chord as seen in a comparison of the two chords.

==Inversions==
:<score lang="lilypond">
{
<<
\override Score.TimeSignature
#'stencil = ##f
\override Score.SpacingSpanner.strict-note-spacing = ##t
\set Score.proportionalNotationDuration = #(ly:make-moment 1/4)
\time 4/4 
\relative c' { 
   <g b d f>1^\markup { \column { "Root" "position" } }
   <b d f g>1^\markup { \column { "First" "inversion" } }
   <d f g b>1^\markup { \column { "Second" "inversion" } }
   <f g b d>1^\markup { \column { "Third" "inversion" } }
   }
  \figures {
    <7>1 <6 5> <4 3> <4 2>
  }
>>
}
</score>

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

*{{music|7 chord}}: GBDF
*{{music|65}}: BDFG
*{{music|43 chord}}: DFGB
*{{music|2}} or {{sup sub|4|2}}: FGBD
Additional numbers are used to indicate the seventh chords and their inversions.<ref>[https://hkpiano.net/wiki/seventh-chord-2/ Seventh chord - Inversions] - ''HK Piano''</ref>

==See also==
*[[Dominant seventh flat five chord]]
*[[Diminished major seventh chord]]
*[[Diminished minor seventh chord]]
*[[Augmented major seventh chord]]
*[[Augmented minor seventh chord]]

==References==
{{Reflist}}

==External links==
* [http://www.fretjam.com/guitar-chord-theory-3.html 7th Chords on guitar], fretjam.com
* [https://www.jazzguitar.be/blog/17-essential-jazz-guitar-chords-beginners/ "17 Easy Jazz Guitar Chords For Beginners"], Dirk Laukens, jazzguitar.be

{{Chords}}
{{Authority control}}

[[Category:Seventh chords| ]]