In a

musical composition Musical composition can refer to an original piece or work of music, either vocal or instrumental, the structure of a musical piece or to the process of creating or writing a new piece of music. People who create new compositions are called ...

, a chord progression or harmonic progression (informally chord changes, used as a plural) is a succession of

chord Chord may refer to: * Chord (music), an aggregate of musical pitches sounded simultaneously ** Guitar chord a chord played on a guitar, which has a particular tuning * Chord (geometry), a line segment joining two points on a curve * Chord ( ...

s. Chord progressions are the foundation of

harmony In music, harmony is the process by which individual sounds are joined together or composed into whole units or compositions. Often, the term harmony refers to simultaneously occurring frequencies, pitches ( tones, notes), or chords. However ...

in Western musical tradition from the common practice era of

Classical music Classical music generally refers to the art music of the Western world, considered to be distinct from Western folk music or popular music traditions. It is sometimes distinguished as Western classical music, as the term "classical music" also ...

to the 21st century. Chord progressions are the foundation of Western popular music styles (e.g., pop music, rock music), traditional music, as well as genres such as

blues Blues is a music genre and musical form which originated in the Deep South of the United States around the 1860s. Blues incorporated spirituals, work songs, field hollers, shouts, chants, and rhymed simple narrative ballads from the Afr ...

and jazz. In these genres, chord progressions are the defining feature on which melody and rhythm are built. In tonal music, chord progressions have the function of either establishing or otherwise contradicting a tonality, the technical name for what is commonly understood as the "

key Key or The Key may refer to: Common meanings * Key (cryptography), a piece of information that controls the operation of a cryptography algorithm * Key (lock), device used to control access to places or facilities restricted by a lock * Key (map ...

" of a song or piece. Chord progressions, such as the common chord progression I–vi–ii–V, are usually expressed by

Roman numerals Roman numerals are a numeral system that originated in ancient Rome and remained the usual way of writing numbers throughout Europe well into the Late Middle Ages. Numbers are written with combinations of letters from the Latin alphabet, eac ...

in Classical music theory. In many styles of popular and traditional music, chord progressions are expressed using the name and " quality" of the chords. For example, the previously mentioned chord progression, in the key of C major, would be written as C major–A minor–D minor–G major in a fake book or lead sheet. In the first chord, C major, the "C" indicates that the chord is built on the

root note In music theory, the concept of root is the idea that a chord can be represented and named by one of its notes. It is linked to harmonic thinking—the idea that vertical aggregates of notes can form a single unit, a chord. It is in this sense ...

"C" and the word "major" indicates that a major chord is built on this "C" note. In rock and blues, musicians also often refer to chord progressions using

, as this facilitates transposing a song to a new key. For example, rock and blues musicians often think of the

12-bar blues The 12-bar blues (or blues changes) is one of the most prominent chord progressions in popular music. The blues progression has a distinctive form in lyrics, phrase, chord structure, and duration. In its basic form, it is predominantly based on ...

as consisting of I, IV, and V chords. Thus, a simple version of the 12-bar blues might be expressed as I–I–I–I, IV–IV–I–I, V–IV–I–I. By thinking of this blues progression in Roman numerals, a backup band or

rhythm section A rhythm section is a group of musicians within a music ensemble or band that provides the underlying rhythm, harmony and pulse of the accompaniment, providing a rhythmic and harmonic reference and "beat" for the rest of the band. The rhythm sec ...

could be instructed by a

bandleader A bandleader is the leader of a music group such as a rock or pop band or jazz quartet. The term is most commonly used with a group that plays popular music as a small combo or a big band, such as one which plays jazz, blues, rhythm and blues or ...

to play the chord progression in any key. For example, if the bandleader asked the band to play this chord progression in the key of C major, the chords would be C–C–C–C, F–F–C–C, G–F–C–C; if the bandleader wanted the song in G major, the chords would be G–G–G–G, C–C–G–G, D–C–G–G; and so on. The complexity of a chord progression varies from genre to genre and over different historical periods. Some pop and rock songs from the 1980s to the 2010s have fairly simple chord progressions.

Funk Funk is a music genre that originated in African American communities in the mid-1960s when musicians created a rhythmic, danceable new form of music through a mixture of various music genres that were popular among African Americans in the m ...

emphasizes the groove and rhythm as the key element, so entire funk songs may be based on one chord. Some jazz-funk songs are based on a two-, three-, or four-chord vamp. Some punk and hardcore punk songs use only a few chords. On the other hand, bebop jazz songs may have 32-bar song forms with one or two chord changes every bar.

Basic theory

A chord may be built upon any note of a musical scale. Therefore, a seven-note

diatonic scale In music theory, a diatonic scale is any heptatonic scale that includes five whole steps (whole tones) and two half steps (semitones) in each octave, in which the two half steps are separated from each other by either two or three whole steps, ...

allows seven basic diatonic triads, each degree of the scale becoming the root of its own chord. A chord built upon the note E is an E chord of some

type Type may refer to: Science and technology Computing * Typing, producing text via a keyboard, typewriter, etc. * Data type, collection of values used for computations. * File type * TYPE (DOS command), a command to display contents of a file. * Ty ...

(major, minor, diminished, etc.) Chords in a progression may also have more than three notes, such as in the case of a seventh chord (V⁷ is particularly common) or an

extended chord In music, extended chords are certain chords (built from thirds) or triads with notes ''extended'', or added, beyond the seventh. Ninth, eleventh, and thirteenth chords are extended chords. The thirteenth is the farthest extension diatonical ...

. The harmonic function of any particular chord depends on the context of the particular chord progression in which it is found. Schoenberg, Arnold. ''Structural Functions of Harmony'', Norton, 1954, p. 1.

Diatonic and chromatic chords

The diatonic harmonization of any major scale results in three major triads, which are based on the first, fourth, and fifth

scale degree In music theory, the scale degree is the position of a particular note on a scale relative to the tonic, the first and main note of the scale from which each octave is assumed to begin. Degrees are useful for indicating the size of intervals and ...

s. The triads are referred to as the tonic chord (in

Roman numeral analysis In music theory, Roman numeral analysis is a type of musical analysis in which chords are represented by Roman numerals (I, II, III, IV, …). In some cases, Roman numerals denote scale degrees themselves. More commonly, however, they represent t ...

, symbolized by "I"), the

subdominant chord In music, the subdominant is the fourth tonal degree () of the diatonic scale. It is so called because it is the same distance ''below'' the tonic as the dominant is ''above'' the tonicin other words, the tonic is the dominant of the subdominan ...

(IV), and the dominant chord, (V), respectively. These three triads include, and therefore can

harmonize In music, harmonization is the chordal accompaniment to a line or melody: "Using chords and melodies together, making harmony by stacking scale tones as triads". A harmonized scale can be created by using each note of a musical scale as a ...

, every note of that scale. Many simple traditional music, folk music and rock and roll songs use only these three chord types (e.g. The Troggs' "

Wild Thing Wild Thing or Wild Things can refer to: Books and comics * Wild Thing (comics), a 1999 Marvel Comics superheroine in the MC2 alternate future * ''The Wild Things'', a 2009 novel written by Dave Eggers Film and television * ''Wild Thing'' (film), ...

", which uses I, IV and V chords). The same major scale also has three

minor chord In music theory, a minor chord is a chord that has a root, a minor third, and a perfect fifth. When a chord comprises only these three notes, it is called a minor triad. For example, the minor triad built on C, called a C minor triad, has pit ...

s, the

supertonic chord In music, the supertonic is the second degree () of a diatonic scale, one whole step above the tonic. In the movable do solfège system, the supertonic note is sung as ''re''. The triad built on the supertonic note is called the supertonic chor ...

(ii),

mediant chord In music, the mediant (''Latin'': to be in the middle) is the third scale degree () of a diatonic scale, being the note halfway between the tonic and the dominant.Benward & Saker (2003), p.32. In the movable do solfège system, the mediant note ...

(iii), and

submediant chord In music, the submediant is the sixth degree () of a diatonic scale. The submediant ("lower mediant") is named thus because it is halfway between tonic and subdominant ("lower dominant") or because its position below the tonic is symmetrical to t ...

(vi), respectively. These chords stand in the same relationship to one another (in the

relative minor key In music, relative keys are the major and minor scales that have the same key signatures (enharmonically equivalent), meaning that they share all the same notes but are arranged in a different order of whole steps and half steps. A pair of major an ...

) as do the three major chords, so that they may be viewed as the first (i), fourth (iv) and fifth (v) degrees of the relative minor key. For example, the relative minor of C major is A minor, and in the key of A minor, the i, iv and v chords are A minor, D minor and E minor. In practice, in a minor key, the

third Third or 3rd may refer to: Numbers * 3rd, the ordinal form of the cardinal number 3 * , a fraction of one third * Second#Sexagesimal divisions of calendar time and day, 1⁄60 of a ''second'', or 1⁄3600 of a ''minute'' Places * 3rd Street (d ...

of the dominant chord is often raised by one semitone to form a major chord (or a

dominant seventh chord In music theory, a dominant seventh chord, or major minor seventh chord, is a seventh chord, usually built on the fifth degree of the major scale, and composed of a root, major third, perfect fifth, and minor seventh. Thus it is a major triad tog ...

if the seventh is added). In addition, the seventh degree of the major scale (i.e. the leading tone) forms a

diminished chord In music theory, a diminished triad (also known as the minor flatted fifth) is a triad consisting of two minor thirds above the root. It is a minor triad with a lowered ( flattened) fifth. When using chord symbols, it may be indicated by the ...

(vii). A chord may also have

chromatic Diatonic and chromatic are terms in music theory that are most often used to characterize scales, and are also applied to musical instruments, intervals, chords, notes, musical styles, and kinds of harmony. They are very often used as a pair, ...

notes, that is, notes outside of the diatonic scale. Perhaps the most basic chromatic

alteration Alteration(s) may refer to: * Alteration (music), the use of a neighboring pitch in the chromatic scale in place of its diatonic neighbor. ** Alteration, in the mensural notation used by renaissance music, the lengthening of a breve, semibreve or ...

in simple folk songs is the raised fourth degree () that results when the

of the ii chord is raised one semitone. Such a chord typically functions as the

secondary dominant A secondary chord is an analytical label for a specific harmonic device that is prevalent in the tonal idiom of Western music beginning in the common practice period: the use of diatonic functions for tonicization. Secondary chords are a typ ...

of the V chord (V/V). In some instances, chromatic notes are introduced to modulate to a new key. This in turn may lead to a

resolution Resolution(s) may refer to: Common meanings * Resolution (debate), the statement which is debated in policy debate * Resolution (law), a written motion adopted by a deliberative body * New Year's resolution, a commitment that an individual mak ...

back to the original key later on, so that the entire sequence of chords helps create an extended

musical form In music, ''form'' refers to the structure of a musical composition or musical improvisation, performance. In his book, ''Worlds of Music'', Jeff Todd Titon suggests that a number of organizational elements may determine the formal structure of a ...

and a sense of movement.

Progressions

Although there are many possible progressions, in practice, progressions are often limited to a few bars' lengths and certain progressions are favored above others. There is also a certain amount of fashion in which a chord progression is defined (e.g., the

progression) and may even help in defining an entire genre. In western classical notation, chords are numbered with Roman numerals. Other types of

chord notation 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 ...

have been devised, from figured bass to the chord chart. These usually allow or even require a certain amount of

improvisation Improvisation is the activity of making or doing something not planned beforehand, using whatever can be found. Improvisation in the performing arts is a very spontaneous performance without specific or scripted preparation. The skills of impr ...

Common progressions

Simple progressions

Diatonic Diatonic and chromatic are terms in music theory that are most often used to characterize Scale (music), scales, and are also applied to musical instruments, Interval (music), intervals, Chord (music), chords, Musical note, notes, musical sty ...

scales such as the major and minor scales lend themselves particularly well to the construction of common chords because they contain many

perfect fifth In music theory, a perfect fifth is the Interval (music), musical interval corresponding to a pair of pitch (music), pitches with a frequency ratio of 3:2, or very nearly so. In classical music from Western culture, a fifth is the interval fro ...

s. Such scales predominate in those regions where harmony is an essential part of music, as, for example, in the common practice period of western classical music. In considering Arab and Indian music, where diatonic scales are used, there are also available a number of non-diatonic scales, the music has no chord changes, remaining always upon the key-chord, an attribute which has also been observed in

hard rock Hard rock or heavy rock is a loosely defined subgenre of rock music typified by aggressive vocals and distorted electric guitars. Hard rock began in the mid-1960s with the garage, psychedelic and blues rock movements. Some of the earliest hard ...

, hip hop,

funk Funk is a music genre that originated in African American communities in the mid-1960s when musicians created a rhythmic, danceable new form of music through a mixture of various music genres that were popular among African Americans in the m ...

disco Disco is a genre of dance music and a subculture that emerged in the 1970s from the United States' urban nightlife scene. Its sound is typified by four-on-the-floor beats, syncopated basslines, string sections, brass and horns, electric pia ...

, jazz, etc. Alternation between two chords may be thought of as the most basic chord progression. Many well-known pieces are built harmonically upon the mere repetition of two chords of the same scale. For example, many of the more straightforward melodies in classical music consist entirely or mostly of alternation between the tonic (I) and the dominant (V, sometimes with an added seventh), as do popular songs such as " Achy Breaky Heart". The Isley Brothers' " Shout" uses I–vi throughout.

Three-chord progressions

Three-chord progression are more common since a melody may then dwell on any note of the scale. They are often presented as successions of four chords (as shown below), in order to produce a binary harmonic rhythm, but then two of the four chords are the same. * * * * Often the chords may be selected to fit a pre-conceived melody, but just as often it is the progression itself that gives rise to the melody. Similar progressions abound in African popular music. They may be varied by the addition of sevenths (or other

scale degrees In music theory, the scale degree is the position of a particular note on a scale relative to the tonic, the first and main note of the scale from which each octave is assumed to begin. Degrees are useful for indicating the size of intervals an ...

) to any chord or by substitution of the relative minor of the IV chord to give, for example, I–ii–V. This sequence, using the ii chord, is also used cadentially in a common chord progression of jazz harmony, the so-called ii–V–I turnaround. Three-chord progressions provide the harmonic foundation of much African and American popular music, and they occur sectionally in many pieces of classical music (such as the opening bars of Beethoven's ''Pastoral'' Symphony). Where such a simple sequence does not represent the entire harmonic structure of a piece, it may readily be extended for greater variety. Frequently, an opening phrase has the progression I–IV–V–V, which ends on an unresolved dominant, may be " answered" by a similar phrase that resolves back onto the tonic chord, giving a structure of double the length: : Additionally, such a passage may be alternated with a different progression to give a simple binary or ternary form such as that of the popular

32-bar form The 32-bar form, also known as the AABA song form, American popular song form and the ballad form, is a song structure commonly found in Tin Pan Alley songs and other American popular music, especially in the first half of the 20th century. A ...

(see

Blues changes

The

and its many variants use an elongated, three-line form of the I–IV–V progression that has also generated countless hit records, including the most significant output of rock and rollers such as Chuck Berry and

Little Richard Richard Wayne Penniman (December 5, 1932 – May 9, 2020), known professionally as Little Richard, was an American musician, singer, and songwriter. He was an influential figure in popular music and culture for seven decades. Described as the " ...

. In its most elementary form (and there are many variants), the chord progression is : Blues progressions have also been subjected to densely chromatic elaboration, as in the Bird blues. Steedman (1984) proposed that a set of recursive

rewrite rule In mathematics, computer science, and logic, rewriting covers a wide range of methods of replacing subterms of a formula with other terms. Such methods may be achieved by rewriting systems (also known as rewrite systems, rewrite engines, or redu ...

s generate all well-formed

transformation Transformation may refer to: Science and mathematics In biology and medicine * Metamorphosis, the biological process of changing physical form after birth or hatching * Malignant transformation, the process of cells becoming cancerous * Trans ...

s of jazz, both basic blues chord changes and slightly modified sequences (such as the "

rhythm changes Rhythm changes are a common 32-bar chord progression in jazz, originating as the chord progression for George Gershwin's "I Got Rhythm". The progression is in AABA form, with each A section based on repetitions of the ubiquitous I–vi–ii–V s ...

"). Important transformations include: * replacement of (or addition to) a chord with its dominant, subdominant or the tritone substitution. * use of chromatic passing chords. * extensively applying the ii–V–I turnaround. * chord alterations such as minor chords, diminished sevenths, etc.

1950s progression

Another common way of extending the I–IV–V progression is by adding the chord of the sixth scale degree, giving the sequence I–vi–IV–V or I–vi–ii–V, sometimes called the

50s progression The 50s progression (also known as the "Heart and Soul" chords, the "Stand by Me" changes, the doo-wop progression and the "ice cream changes") is a chord progression and turnaround used in Western popular music. The progression, represented in Ro ...

or doo-wop progression. This progression had been in use from the earliest days of classical music and then generated popular hits such as Rodgers and Hart's "

Blue Moon A blue moon is an additional full moon that appears in a subdivision of a year: the third of four full moons in a season. The phrase in modern usage has nothing to do with the actual color of the Moon, although a visually blue Moon (the Moon a ...

" (1934) and Hoagy Carmichael's " Heart and Soul" (1938). Taken up into the pop mainstream, it continued to be used sectionally, as in the last part of The Beatles' " Happiness Is a Warm Gun".

Circle progressions

Introducing the ii chord into these progressions emphasises their appeal as constituting elementary forms of

circle progression A circle is a shape consisting of all points in a plane that are at a given distance from a given point, the centre. Equivalently, it is the curve traced out by a point that moves in a plane so that its distance from a given point is const ...

. These, named for the circle of fifths, consist of "adjacent

roots A root is the part of a plant, generally underground, that anchors the plant body, and absorbs and stores water and nutrients. Root or roots may also refer to: Art, entertainment, and media * ''The Root'' (magazine), an online magazine focusing ...

in ascending fourth or descending fifth relationship"—for instance, the sequence vi–ii–V–I ascends with each successive chord to one a fourth above the previous. Such a motion, based upon close harmonic relations, offers "undoubtedly the most common and the strongest of all harmonic progressions". Short cyclical progressions may be derived by selecting a sequence of chords from the series completing a circle from the tonic through all seven diatonic chords:

I–IV–vii^o–iii–vi–ii–V–I

This type of progression was much used by classical composers, who introduced increasingly subtle inflections. Particularly, substitution of major for minor chords giving, for example, I–VI–II–V allowed a more sophisticated

chromaticism Chromaticism is a compositional technique interspersing the primary diatonic scale, diatonic pitch (music), pitches and chord (music), chords with other pitches of the chromatic scale. In simple terms, within each octave, diatonic music uses o ...

as well as the possibility of

modulation In electronics and telecommunications, modulation is the process of varying one or more properties of a periodic waveform, called the ''carrier signal'', with a separate signal called the ''modulation signal'' that typically contains informatio ...

. These harmonic conventions were taken up by American popular entertainers, giving rise to many variations on those harmonic staples of early jazz that have been dubbed the

ragtime progression Ragtime, also spelled rag-time or rag time, is a musical style that flourished from the 1890s to 1910s. Its cardinal trait is its syncopated or "ragged" rhythm. Ragtime was popularized during the early 20th century by composers such as Scott J ...

and the stomp progression. All such progressions may be found used sectionally, as for example in the much-used "

" of George Gershwin's " I Got Rhythm".

Harmonizing the scale

As well as the cyclical underpinning of chords, the ear tends to respond well to a linear thread; chords following the scale upwards or downwards. These are often referred to as step progressions because they follow the steps of the scale, making the scale itself a

bassline Bassline (also known as a bass line or bass part) is the term used in many styles of music, such as blues, jazz, funk, Dub music, dub and electronic music, electronic, traditional music, traditional, or classical music for the low-pitched Part ( ...

. In the 17th century, descending bass lines found favour for "divisions on the ground", so that Pachelbel's canon contains very similar harmonizations of the descending major scale. At its simplest, this descending sequence may simply introduce an extra chord, either III or V, into the I–vi–IV–V type of sequence described above. This chord allows the harmonization of the seventh degree, and so of the bass line I–VII–VI.... The finale measures of the first movement of Ravel's

Piano Concerto in G Maurice Ravel's Piano Concerto in G major, was composed between 1929 and 1931. The concerto is in three movements, with a total playing time of a little over 20 minutes. Ravel said that in this piece he was not aiming to be profound but to enterta ...

feature the harmonization of a descending hybrid scale ( phrygo-major). In this special case, Ravel used a parallel series of major triads (G F E D C B A G).

Minor and modal progressions

Similar strategies to all the above, work equally well in minor modes: there have been one-, two-, and three-minor-chord songs,

minor blues ''Minor Blues'' is an album by pianist Kenny Barron recorded in New York in 2009 and released on the Japanese Venus label.Fitzgerald, MKenny Barron Discography accessed January 24, 2019 Reception In the review on AllMusic, Ken Dryden noted "Th ...

. A notable example of a descending minor chord progression is the four-chord

Andalusian cadence The Andalusian cadence (diatonic phrygian tetrachord) is a term adopted from flamenco music for a chord progression comprising four chords descending stepwise – a iv–III–II–I progression with respect to the Phrygian mode or i–VII–VI� ...

, i–VII–VI–V. Folk and blues tunes frequently use the Mixolydian scale, which has a flat seventh degree, altering the position of the three major chords to I–VII–IV. For example, if the major scale of C, which gives the three chords C, F and G on the first, fourth and fifth degrees, is played with G as the tonic, then the same chords will now appear on the first, fourth, and seventh degrees. A common chord progression with these chords is I-VII–IV-I, which also can be played as I-I-VII–IV or VII–IV-I-I. The minor-third step from a minor key up to the

relative major In music, relative keys are the major and minor scales that have the same key signatures (enharmonically equivalent), meaning that they share all the same notes but are arranged in a different order of whole steps and half steps. A pair of major an ...

encouraged ascending scale progressions, particularly based on an ascending pentatonic scale. Typical of the type is the sequence i–III–IV (or iv)–VI. According to Tom Sutcliffe: This came about partly from the similarity of the blues scale to modal scales and partly from the characteristics of the guitar and the use of parallel major chords on the

pentatonic minor scale A pentatonic scale is a musical scale with five notes per octave, in contrast to the heptatonic scale, which has seven notes per octave (such as the major scale and minor scale). Pentatonic scales were developed independently by many ancie ...

. With barre chords on guitar, the same chord shape can be moved up and down the neck without changing the fingering. This phenomenon is also linked to the rise in use of power chords in various sub-genres of rock music.