Chord (music)

A guitar player performing a C chord with G bass.

A chord, in music, is any harmonic set of pitches consisting of two or more (usually three or more) notes (also called "pitches") that are heard as if sounding simultaneously.[1][2] (For many practical and theoretical purposes, arpeggios and broken chords, or sequences of chord tones, may also be considered as chords.)

Chords and sequences of chords are frequently used in modern West African[3] and Oceanic music,[4] Western classical music, and Western popular music; yet, they are absent from the music of many other parts of the world.[5]

In tonal Western classical music (music with a tonic key or "home key"), the most frequently encountered chords are triads, so called because they consist of three distinct notes: the root note, and Intervals of a third and a fifth above the root note. Other chords with more than three notes include added tone chords, extended chords and tone clusters, which are used in contemporary classical music, jazz and other genres.

An ordered series of chords is called a chord progression.[6] One example of a widely used chord progression in Western traditional music and blues is the 12 bar blues progression. Although any chord may in principle be followed by any other chord, certain patterns of chords are more common in Western music, and some patterns have been accepted as establishing the key (tonic note) in common-practice harmony–notably the movement between tonic and dominant chords.[citation needed] To describe this, Western music theory has developed the practice of numbering chords using Roman numerals[7] which represent the number of diatonic steps up from the tonic note of the scale.

Common ways of notating or representing chords[8] in Western music (other than conventional staff notation) include Roman numerals, the Nashville number system, figured bass, macro symbols (sometimes used in modern musicology), and chord charts.

Definition and history

Mussorgsky's Pictures at an Exhibition "Promenade", is a piece showing an explicit chord progression.(Nattiez 1990, p. 218) About this soundPlay 

The English word chord derives from Middle English cord, a shortening of accord[9] in the original sense of agreement and later, harmonious sound.[10] A sequence of chords is known as a chord progression or harmonic progression. These are frequently used in Western music.[5] A chord progression "aims for a definite goal" of establishing (or contradicting) a tonality founded on a key, root or tonic chord.[7] The study of harmony involves chords and chord progressions, and the principles of connection that govern them.[11]

Ottó Károlyi[12] writes that, "Two or more notes sounded simultaneously are known as a chord," though, since instances of any given note in different octaves may be taken as the same note, it is more precise for the purposes of analysis to speak of distinct pitch classes. Furthermore, as three notes are needed to define any common chord, three is often taken as the minimum number of notes that form a definite chord.[13] Hence Andrew Surmani, for example, (2004, p. 72) states, "When three or more notes are sounded together, the combination is called a chord." George T. Jones (1994, p. 43) agrees: "Two tones sounding together are usually termed an interval, while three or more tones are called a chord." According to Monath (1984, p. 37); "A chord is a combination of three or more tones sounded simultaneously," and the distances between the tones are called intervals. However sonorities of two pitches, or even single-note melodies, are commonly heard as implying chords.[14] A simple example of two notes being interpreted as a chord is when the root and third are played, but the fifth is omitted. In the key of C major, if the music comes to rest on the two notes G and B, most listeners will hear this as a G major chord.

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.

Upper stave: Claude Debussy's Première Arabesque. The chords on the lower stave are constructed from the notes in the actual piece, shown on the upper stave. About this soundPlay 

In the medieval era, early Christian hymns featured organum (which used the simultaneous perfect intervals of a fourth, a fifth, and an octave[15]), with chord progressions and harmony an incidental result of the emphasis on melodic lines during the medieval and then Renaissance (15th to 17th centuries).[16][17]

The Baroque period, the 17th and 18th centuries, began to feature the major and minor scale based tonal system and harmony, including chord progressions and circle progressions.[18] It was in the Baroque period that the accompaniment of melodies with chords was developed, as in figured bass,[17] and the familiar cadences (perfect authentic, etc.).[19] In the Renaissance, certain dissonant sonorities that suggest the dominant seventh occurred with frequency.[20] In the Baroque period the dominant seventh proper was introduced, and was in constant use in the Classical and Romantic periods.[20] The leading-tone seventh appeared in the Baroque period and remains in use.[21] Composers began to use nondominant seventh chords in the Baroque period. They became frequent in the Classical period, gave way to altered dominants in the Romantic period, and underwent a resurgence in the Post-Romantic and Impressionistic period.[22]

The Romantic period, the 19th century, featured increased chromaticism.[18] Composers began to use secondary dominants in the Baroque, and they became common in the Romantic period.[23] Many contemporary popular Western genres continue to rely on simple diatonic harmony, though far from universally:[24] notable exceptions include the music of film scores, which often use chromatic, atonal or post-tonal harmony, and modern jazz (especially circa 1960), in which chords may include up to seven notes (and occasionally more).[25] When referring to chords that do not function as harmony, such as in atonal music, the term "sonority" is often used specifically to avoid any tonal implications of the word "chord"[citation needed].

Triads consist of three notes; the root or first note, the third, and the fifth.[26] 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.

Other Languages
العربية: تآلف (موسيقى)
asturianu: Acorde
azərbaycanca: Akkord
Bân-lâm-gú: Hô-im
беларуская: Акорд
беларуская (тарашкевіца)‎: Акорд
български: Акорд
čeština: Akord
Deutsch: Akkord
eesti: Akord
Ελληνικά: Συγχορδία
español: Acorde
Esperanto: Akordo (muziko)
euskara: Akorde
فارسی: آکورد
français: Accord (musique)
Gaeilge: Corda (ceol)
galego: Acorde
한국어: 화음
հայերեն: Ակորդ
hrvatski: Akord
Bahasa Indonesia: Akord
עברית: אקורד
қазақша: Аккорд
Кыргызча: Аккорд
latviešu: Akords
lietuvių: Akordas
magyar: Akkord
македонски: Акорд
მარგალური: აკორდი (მუსიკა)
Nederlands: Akkoord (muziek)
日本語: 和音
oʻzbekcha/ўзбекча: Akkord
polski: Akord
português: Acorde
română: Acord (muzică)
русский: Аккорд
shqip: Akordi
Simple English: Chord
slovenčina: Akord (hudba)
slovenščina: Akord
српски / srpski: Акорд
srpskohrvatski / српскохрватски: Akord
suomi: Sointu
svenska: Ackord
тоҷикӣ: Аккорд
Türkçe: Akor
тыва дыл: Аккорд
українська: Акорд
Tiếng Việt: Hợp âm
文言: 和弦
吴语: 和弦
粵語: 和弦
中文: 和弦