- This article describes pitch simultaneity and harmony in music. For other meanings of the word, see Chord.
A chord in 
The most frequently encountered chords are inversion, the order in which their notes are stacked.
However, since the structural meaning of a chord depends exclusively upon the “head arrange” a part.
Definition and history
The English word “chord” derives from Middle English “cord”, a shortening of “accord”
For a sound configuration to be recognized as a chord it must have a certain duration. But, since a chord may be understood as such even when all its notes are not simultaneously audible, there has been some academic discussion regarding the point at which a group of notes may be called a chord. Jean-Jacques Nattiez (1990, p. 218) explains that “we can encounter ‘pure chords’ in a musical work,” such as in the “Promenade” of Modest Mussorgsky‘s Pictures at an Exhibition but “often, we must go from a textual given to a more abstract representation of the chords being used” – as in Claude Debussy’s Première Arabesque.
In the 
Triads consist of three notes; the “root” or “first” note, the “third” and the “fifth”. For example the C major scale consists of the notes C D E F G A B: a triad can be constructed on any note of such a major scale, and all are minor or major except the triad on the seventh or leading-tone, which is a diminished chord. A triad formed using the note C itself consists of C (the root note), E (the third note of the scale) and G (the fifth note of the scale). The interval from C to E is of four semitones, a major third, and so this triad is called C Major. A triad formed upon the same scale but with D as the root note, D (root), F (third), A (fifth), on the other hand, has only three semitones between the root and third and is called D minor, a minor triad.
Chords can be represented in various ways. The most common notation systems are:
- Plain staff notation, used in classical music (see figure).
- Roman numeral analysis.
- improvise chords with the right hand while playing the bass with their left.
- musicology, to denote chord root and quality.
- Various vamp on it.
While scale degrees are typically represented with Arabic numerals, the triads that have these degrees as their roots are often identified by Roman numerals. In some conventions (as in this and related articles) upper-case Roman numerals indicate major triads while lower-case Roman numerals indicate minor triads: other writers, (e.g. Schoenberg) use upper case Roman numerals for both major and minor triads. Some writers use upper-case Roman numerals to indicate the chord is diatonic in the major scale, and lower-case Roman numerals to indicate that the chord is diatonic in the minor scale. Diminished triads may be represented by lower-case Roman numerals with a degree symbol. It should be noted that Roman numerals may also be used in notation for stringed instruments to indicate the position or string to be played.
Figured bass notation
Figured bass or thoroughbass is a kind of musical notation used in almost all Baroque music, though rarely in modern music, to indicate harmonies in relation to a conventionally written bass line. Figured bass is closely associated with basso continuo accompaniment. Added numbers and accidentals beneath the staff indicate at the intervals to be played, the numbers stand for the number of scale steps above the written note that the figured notes should be played.
In the illustration the bass note is a C, and the numbers 4 and 6 indicate that notes a fourth and a sixth above, that is F and A, should be played, giving the second inversion of the F major triad.
Macro analysis uses upper-case and lower-case letters to indicate the roots of chords, followed by symbols that specify the chord quality.
In most rock, a chord name and the corresponding symbol are typically composed of one or more of the following parts:
- The root note (e.g. C).
- The chord quality (e.g. major, maj, or M).
- The major seventh, maj7, or M7).
- The altered fifth (e.g. sharp five, or ♯5).
- An additional interval number (e.g. add 13 or add13), in added tone chords.
For instance, the name C augmented seventh, and the corresponding symbol Caug7, or C+7, are both composed of parts 1, 2, and 3.
None of these parts, except for the root, directly refer to the notes forming the chord, but to the intervals they form with respect to the root. For instance, Caug7 is formed by the notes C-E-G♯-B♭. However, its name and symbol refer only to the root note C, the augmented (fifth) interval from C to G♯, and the (minor) seventh interval from C to B♭. The interval from C to E (a major third) sets the chord quality (major). A set of decoding rules is applied to deduce the missing information.
Some of the symbols used for chord quality are similar to those used for interval quality:
- m, or min for minor,
- M, maj, or no symbol (see rule 2 below) for major,
- aug for augmented,
- dim for diminished.
In addition, however,
- Δ is sometimes used for major, instead of the standard M, or maj,
- − is sometimes used for minor, instead of the standard m or min,
- +, or aug, is used for augmented (A is not used),
- o, °, dim, is used for diminished (d is not used),
- ø, or Ø is used for half diminished,
- dom is used for dominant.
Every chord has certain characteristics, which include:
- Number of pitch classes (distinct notes without respect to octave) that constitute the chord.
- Scale degree of the root note
- Position or inversion of the chord
- General type of intervals it contains: for example seconds, thirds, or fourths
Number of notes
Two-note combinations, whether referred to as chords or intervals, are called clusters, and polychords.
In the key of C major the first degree of the scale, called the tonic, is the note C itself, so a C major chord, a triad built on the note C, may be called the one chord of that key and notated in Roman numerals as I. The same C major chord can be found in other scales: it forms chord III in the key of A minor (A-B-C) and chord IV in the key of G major (G-A-B-C). This numbering lets us see the job a chord is doing in the current key and tonality.
Many analysts use lower-case Roman numerals to indicate minor triads and upper-case for major ones, and “degree” and “plus” signs ( o and + ) to indicate diminished and augmented triads respectively. Otherwise all the numerals may be upper-case and the qualities of the chords inferred from the scale degree. Chords outside the scale can be indicated by placing a flat/sharp sign before the chord — for example, the chord of E flat major in the key of C major is represented by ♭III. The tonic of the scale may be indicated to the left (e.g. F♯:)or may be understood from a key signature or other contextual clues. Indications of inversions or added tones may be omitted if they are not relevant to the analysis. Roman numerals indicate the root of the chord as a key as follows:
|Scale degree||tonic||supertonic||mediant||subdominant||dominant||submediant||leading tone/subtonic|
In the harmony of Western art music a chord is said to be in root position when the tonic note is the lowest in the chord, and the other notes are above it. When the lowest note is not the tonic, the chord is said to be inverted. Chords, having many constituent notes, can have many different inverted positions as shown below for the C major chord:
|Bass note||Position||Order of notes||Notation|
|C||root position||C E G||as G is a 5th above C and E is a 3rd above C|
|E||1st inversion||E G C||as C is a 6th above E and G is a 3rd above E|
|G||2nd inversion||G C E||as E is a 6th above G and C is a 4th above G|
Further, a four-note chord can be inverted to four different positions by the same method as triadic inversion. Where guitar chords are concerned the term “inversion” is used slightly differently; to refer to stock fingering “shapes”.
Secundal, tertian, and quartal chords
Many chords are a sequence of ascending notes separated by intervals of roughly the same size. For example the C minor third. Any such chord that can be decomposed into a series of (major or minor) thirds is called a tertian chord. Most common chords are tertian.
A chord such as C-D-E♭, though, is a series of seconds, containing a minor second (D-E♭). Any such chord that can be decomposed into a series of (major or minor) seconds is called secundal.
The chord C-F-B, consists of a tritone) F-B. Any such chord that can be decomposed into a series of (perfect or augmented) fourths is called quartal.
These terms can become ambiguous when dealing with non-enharmonically equivalent to (and sonically indistinguishable from) the chord C-E-G♯, which is a series of major thirds (C-E and E-G♯).
See also Mixed-interval chord.
Triads, also called triadic chords, are tertian chords (see above) with three notes. The four basic triads are described below.
|Component intervals||Chord symbol||Notes||Audio|
|Major triad||major||perfect||C, CM, CΔ, Cma, Cmaj||C-E-G||info)|
|Minor triad||minor||perfect||Cm, C-, Cmi, Cmin||C-E♭-G||info)|
|Augmented triad||major||augmented||C+, C+, Caug||C-E-G♯||info)|
|Diminished triad||minor||diminished||Cº, Cm(♭5), Cdim||C-E♭-G♭||info)|
Seventh chords are tertian chords (see above), constructed by adding a fourth note to a triad, at the interval of a third above the fifth of the chord. This creates the interval of a seventh above the root of the chord, the next natural step in composing tertian chords. The seventh chord on the fifth step of the scale (the dominant seventh) is the only one available in the major scale: it contains all three notes of the diminished triad of the seventh and is frequently used as a stronger substitute for it.
There are various types of seventh chords depending on the quality of both the chord and the seventh added. In chord notation the chord type is sometimes superscripted and sometimes not (e.g. Dm7, Dm7, and Dm7 are all identical).
|Component intervals||Chord symbol||Notes||Audio|
|Diminished seventh||minor||diminished||diminished||Co7, Cdim7||C E♭ G♭ B||info)|
|Half-diminished seventh||minor||diminished||minor||Cø7, Cm7♭5, C−7(♭5)||C E♭ G♭ B♭||info)|
|Minor seventh||minor||perfect||minor||Cm7, Cmin7, C−7, C−7||C E♭ G B♭||info)|
|Minor major seventh||minor||perfect||major||Cm(M7), Cm maj7, C−(j7), C−Δ7, C−M7||C E♭ G B||info)|
|Dominant seventh||major||perfect||minor||C7, C7, Cdom7||C E G B♭||info)|
|Major seventh||major||perfect||major||CM7, Cmaj7, CΔ7, CΔ7, CΔ7, Cj7||C E G B||info)|
|Augmented seventh||major||augmented||minor||C+7, Caug7, C7+, C7+5, C7♯5||C E G♯ B♭||info)|
|Augmented major seventh||major||augmented||major||C+(M7), CM7+5, CM7♯5, C+j7, C+Δ7||C E G♯ B||info)|
Extended chords are triads with further tertian notes added beyond the seventh; the ninth, eleventh, and thirteenth chords. After the thirteenth any notes added in thirds will duplicate notes elsewhere in the chord: all seven notes of the scale are present in the chord and further added notes will not give new pitch classes. Such chords may be constructed only by using notes that lie outside the diatonic seven-note scale (See #Altered chords below).
|Components (chord and intervals)||Chord symbol||Audio|
|Dominant ninth||dominant seventh chord||major ninth||-||-||C9||info)|
|Dominant eleventh||dominant seventh chord
(the third is usually omitted)
|major ninth||perfect eleventh||-||C11||info)|
|Dominant thirteenth||dominant seventh chord||major ninth||perfect eleventh
Other extended chords follow similar rules, so that for example maj9, maj11, and maj13 contain major seventh chords rather than dominant seventh chords, while min9, min11, and min13 contain minor seventh chords.
Although the third and seventh of the chord are always determined by the symbols shown above, the fifth, ninth, eleventh and thirteenth may all be chromatically altered by accidentals (the root cannot be so altered without changing the name of the chord, while the third cannot be altered without altering the chord’s quality). These are noted alongside the element to be altered. Accidentals are most often used in conjunction with dominant seventh chords. “Altered” dominant seventh chords (C7alt) may have a flat ninth, a sharp ninth, a diminished fifth or an augmented fifth (see Levine’s Jazz Theory). Some write this as C7+9, which assumes also the flat ninth, diminished fifth and augmented fifth (see Aebersold’s Scale Syllabus). The augmented ninth is often referred to in blue note, being enharmonically equivalent to the flat third or tenth. When superscripted numerals are used the different numbers may be listed horizontally (as shown) or else vertically.
|Component notes||Chord symbol||Audio|
|Seventh augmented fifth||dominant seventh||augmented fifth||C7+5, C7♯5||info)|
|Seventh flat ninth||dominant seventh||minor ninth||C7-9, C7♭9||info)|
|Seventh sharp ninth||dominant seventh||augmented ninth||C7+9, C7♯9||info)|
|Seventh augmented eleventh||dominant seventh||augmented eleventh||C7+11, C7♯11||info)|
|Seventh flat thirteenth||dominant seventh||minor thirteenth||C7-13, C7♭13||info)|
|Half-diminished seventh||minor seventh||diminished fifth||Cø, Cm7♭5||info)|
Added tone chords
An added tone chord is a triad chord with an added, non-tertian note, such as the commonly added sixth as well as chords with an added second (ninth) or fourth (eleventh) or a combination of the three. These chords do not include “intervening” thirds as in an extended chord. Added chords can also have variations. Thus madd9, m4 and m6 are minor triads with extended notes.
The major sixth chord (also called, sixth or added sixth with the chord notation 6, e.g., “C6″) is by far the most common type of sixth chord of the first group. It comprises a major triad with the added major sixth above the root, common in popular music. For example, the chord C6 contains the notes C-E-G-A. The minor sixth chord (min6 or m6, e.g., “Cm6″) is a minor triad with the same added note. For example, the chord Cmin6 contains the notes C-E♭-G-A. In chord notation, the sixth of either chord is always assumed to be a major sixth rather than a minor sixth, however a minor sixth interval may be indicated in the notation as, for example, “Cm(m6)”, or Cmm6.
The augmented sixth chord usually appears in chord notation as its enharmonic equivalent, the seventh chord. This chord contains two notes separated by the interval of an augmented sixth (or, by inversion, a diminished third, though this inversion is rare). The augmented sixth is generally used as a dissonant interval most commonly used in motion towards a dominant chord in root position (with the root doubled to create the octave to which the augmented sixth chord resolves) or to a tonic chord in second inversion (a tonic triad with the fifth doubled for the same purpose). In this case, the tonic note of the key is included in the chord, sometimes along with an optional fourth note, to create one of the following (illustrated here in the key of C major):
- Italian augmented sixth: A♭, C, F♯
- French augmented sixth: A♭, C, D, F♯
- German augmented sixth: A♭, C, E♭, F♯
The augmented sixth family of chords exhibits certain peculiarities. Since they are not based on triads, as are seventh chords and other sixth chords, they are not generally regarded as having roots (nor, therefore, inversions), although one re-voicing of the notes is common (with the namesake interval inverted to create a diminished third).
The second group of sixth chords includes inverted major and minor chords, which may be called sixth chords in that the six-three (6/3) and six-four (6/4) chords contain intervals of a sixth with the bass note, though this is not the root. Nowadays this is mostly for academic study or analysis (see figured bass) but the altered tones this chord is often grouped with the borrowed chords (see below) but the chord is not borrowed from the relative major or minor and it may appear in both major and minor keys.
|Component notes (chord and interval)||Chord symbol||Audio|
|Add nine||major triad||major ninth||-||C2, Cadd9||info)|
|Add fourth||major triad||perfect fourth||-||C4, Cadd11||info)|
|Add sixth||major triad||major sixth||-||C6||info)|
|Six-nine||major triad||major sixth||major ninth||C6/9|
|Mixed-third||major triad||minor third||-||info)|
A suspended chord, or “sus chord” (sometimes wrongly thought to mean sustained chord), is a chord in which the third is replaced by either the “second” or the “fourth.” This results in two main chord types: the suspended second (sus2) and the suspended fourth (sus4). The chords, Csus2 and Csus4, for example, consist of the notes C D G and C F G, respectively. There is also a third type of suspended chord, in which both the second and fourth are present, for example the chord with the notes C D F G.”
The name common practice period, in which a stepwise melodic progress to a harmonically stable note in any particular part was often momentarily delayed or suspended by extending the duration of the previous note. The resulting unexpected dissonance could then be all the more satisfyingly resolved by the eventual appearance of the displaced note. In traditional music theory the inclusion of the third in either chord would negate the suspension, so such chords would be called added ninth and added eleventh chords instead.
In modern layman usage the term is restricted to the displacement of the third only and the dissonant second or fourth no longer needs to be held over (“prepared”) from the previous chord. Neither is it now obligatory for the displaced note to make an appearance at all though in the majority of cases the conventional stepwise resolution to the third is still observed. In Maiden Voyage“.
Extended versions are also possible, such as the seventh suspended fourth, which, with root C, contains the notes C F G B♭ and is notated as C7sus4 info). Csus4 is sometimes written Csus since the sus4 is more common than the sus2.
|Component notes (chord and interval)||Chord symbol||Audio|
|Sus2||Open fifth||major second||-||Csus2||info)|
|Sus4||Open fifth||perfect fourth||-||Csus4||info)|
|Jazz sus||Open fifth||m7, P4, M9||-||C9sus4||info)|
For instance, for a composer working in the C major key, a major ♭III chord would be borrowed, as this appears only in the C minor key. Although borrowed chords could theoretically include chords taken from any key other than the home key, this is not how the term is used when a chord is described in formal musical analysis.
When a chord is analysed as “borrowed” from another key it may be shown by the Roman numeral corresponding with that key after a slash so, for example, V/V indicates the dominant chord of the dominant key of the present home-key. The dominant key of C major is G major so this modulation.
- Chord bible
- Elektra chord
- Factor (chord)
- Mystic chord
- Open chord
- Petrushka chord
- Psalms chord
- Spider chord
- Subsidiary chord
- Károlyi, Otto (1965). Introducing Music. Penguin Books. p. 63. “Two or more notes sounding simultaneously are known as a chord.”
- Mitchell, Barry (January 16, 2008). “An explanation for the emergence of Jazz (1956)“, Theory of Music.
- Linkels, Ad, The Real Music of Paradise”, In Broughton, Simon and Ellingham, Mark with McConnachie, James and Duane, Orla (Ed.), World Music, Vol. 2: Latin & North America, Caribbean, India, Asia and Pacific, pp 218–229. Rough Guides Ltd, Penguin Books. ISBN 1-85828-636-0
- Arnold Schoenberg, Structural Functions of Harmony, Faber and Faber, 1983, p.1-2.
- Benward & Saker (2003), p. 77.
- Merriam-Webster, Inc. (1995). “Chord”, Merriam-Webster’s dictionary of English usage, p.243. ISBN 978-0-87779-132-4.
- Dahlhaus, Car. “Harmony”, Grove Music Online, ed. L. Macy (accessed 24 February 2007), grovemusic.com (subscription access).
- Károlyi, Otto, Introducing Music, p. 63. England: Penguin Books.
- Duarter, John (2008). Melody & Harmony for Guitarists, p.49. ISBN 978-0-7866-7688-0.
- Benward & Saker (2003), p.70.
- Benward & Saker (2003), p.100.
- Benward & Saker (2003), p.201.
- Benward & Saker (2003), p.220.
- Benward & Saker (2003), p.231.
- Benward & Saker (2003), p.274.
- Pachet, François, Surprising Harmonies, International Journal on ComputingAnticipatory Systems, 1999. 
- Pen, Ronald (1992). Introduction to Music, p.81. McGraw-Hill, ISBN 0-07-038068-6. “In each case the note that forms the foundation pitch is called the root, the middle tone of the chord is designated the third (because it is separated by the interval of a third from the root), and the top tone is referred to as the fifth (because it is a fifth away from the root).”
- William G Andrews and Molly Sclater (2000). Materials of Western Music Part 1, p.227. ISBN 1-55122-034-2.
- The symbol Δ is ambiguous, as it is used by some as a synonym for M (e.g. CΔ=CM and CΔ7=CM7), and by others as a synonym of M7 (e.g. CΔ=CM7).
- Haerle, Dan (1982). The Jazz Language: A Theory Text for Jazz Composition and Improvisation, p.30. ISBN 978-0-7604-0014-2.
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- Bert Weedon, Play in a Day, Faber Music Ltd, ISBN 0-571-52965-8, passim – among a wide range of other guitar tutors
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- Grout, Donald Jay (1960). A History Of Western Music. Norton Publishing.
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- Goldman (1965). Cited in Nattiez (1990).
- Jones, George T. (1994). HarperCollins College Outline Music Theory. ISBN 0-06-467168-2.
- Nattiez, Jean-Jacques (1990). Music and Discourse: Toward a Semiology of Music (Musicologie générale et sémiologue, 1987). Translated by Carolyn Abbate (1990). ISBN 0-691-02714-5.
- Norman Monath, Norman (1984). How To Play Popular Piano In 10 Easy Lessons. Fireside Books. ISBN 0-671-53067-4.
- Stanley Sadie and John Tyrrell, eds. (2001). The New Grove Dictionary of Music and Musicians. ISBN 1-56159-239-0.
- Surmani, Andrew (2004). Essentials of Music Theory: A Complete Self-Study Course for All Musicians. ISBN 0-7390-3635-1.
- Schejtman, Rod (2008). Music Fundamentals. The Piano Encyclopedia. ISBN 978-987-25216-2-2. http://www.pianoencyclopedia.com.
- Benward, Bruce & Saker, Marilyn (2002). Music in Theory and Practice, Volumes I & II (7th ed.). New York: McGraw Hill. ISBN 0-07-294262-2.