The twelve-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 the I, IV, and V chords of a key. Mastery of the blues and rhythm changes are "critical elements for building a jazz repertoire". [1]
The blues originated from a combination of work songs, spirituals, and early southern country music. [2] The music was passed down through oral tradition. It was first written down by W. C. Handy, an African American composer and band leader. Its popularity led to the creation of "race records" and the popularity of blues singers like Bessie Smith and Ma Rainey. [3] The style of music heard on race records was later called "rhythm and blues" (R & B). As the music became more popular, more people wanted to perform it. General patterns that existed in the blues were formalized, one of these being the 12-bar blues. [2]
The basic progression for a 12-bar blues may be represented in several ways. It is shown in its simplest form, without the common "quick change", turnarounds, or seventh chords. For variations, see the following section.
| C | C | C | C |
| F | F | C | C |
| G | G | C | C |
| T | T | T | T |
| S | S | T | T |
| D | D | T | T |
| I | I | I | I |
| IV | IV | I | I |
| V | V | I | I |
In the original form, the dominant chord continued through the tenth bar; later on, the V–IV–I–I "shuffle blues" pattern became standard in the third set of four bars: [6]
| I | I | I | I |
| IV | IV | I | I |
| V | IV | I | I |
The common quick-change, quick to four, or quick four variation uses the subdominant or IV chord in the second bar. [7]
| I | IV | I | I |
| IV | IV | I | I |
| V | V | I | I |
Seventh chords are a type of chord that includes the 7th scale degree (that is, the 7th note of the scale). There are different types of 7th chords such as major 7ths, dominant 7ths, minor 7ths, half diminished 7ths, and fully diminished 7ths. [8] These chords are similar with slight changes, but are all centered around the same key center. Dominant 7th chords are generally used throughout a blues progression. The addition of dominant 7th chords as well as the inclusion of other types of 7th chords (i.e. minor and diminished 7ths) are often used just before a change, and more changes can be added. A more complicated example might look like this, where "7" indicates a seventh chord:
| I | IV | I | I7 |
| IV | IV7 | I | I7 |
| V | IV | I | V7 |
This progression is similar to Charlie Parker's "Now's the Time", "Billie's Bounce", Sonny Rollins's "Tenor Madness", and many other bop tunes. [9] Peter Spitzer describes it as "a bop soloist's cliche to arpeggiate this chord [A7♭9 (V/ii = VI7♭9)] from the 3 up to the ♭ 9." [9]
| I7 | IV7 | I7 | V7 I7 |
| IV7 | ♯IVo7 | I7 | V/ii♭9 |
| ii7 | V7 | I7 V/ii♭9 | ii7 V7 |
There are also minor twelve-bar blues, such as John Coltrane's "Equinox" and "Mr. P.C.". [10] The chord on the fifth scale degree may be major (V7) or minor (v7). [10] Major and minor can also be mixed together, a signature characteristic of the music of Charles Brown. [11]
| i7 | i7 | i7 | i7 |
| iv7 | iv7 | i7 | i7 |
| ♭VI7 | V7 | i7 | i7 |
"W. C. Handy codified this blues form to help musicians communicate chord changes." [12] Many variations are possible. The length of sections may be varied to create eight-bar blues or sixteen-bar blues.
As the chords of a 12-bar blues follow a form, so does the melodic line. The melodic line might just be the melody of the piece or it might also include lyrics. The melody and lyrics frequently follow an AA'B form, meaning one phrase is played then repeated (perhaps with a slight alteration), then something new is played. [14] This pattern is frequently used in the blues and in musical genres that have their roots in the blues. [15]
An altered chord is a chord that replaces one or more notes from the diatonic scale with a neighboring pitch from the chromatic scale. By the broadest definition, any chord with a non-diatonic chord tone is an altered chord. The simplest example of altered chords is the use of borrowed chords, chords borrowed from the parallel key, and the most common is the use of secondary dominants. As Alfred Blatter explains, "An altered chord occurs when one of the standard, functional chords is given another quality by the modification of one or more components of the chord."
The term blues scale refers to several different scales with differing numbers of pitches and related characteristics. A blues scale is often formed by the addition of an out-of-key "blue note" to an existing scale, notably the flat fifth addition to the minor pentatonic scale. However, the heptatonic blues scale can be considered a major scale with altered intervals.
In a musical composition, a chord progression or harmonic progression is a succession of chords. Chord progressions are the foundation of harmony in Western musical tradition from the common practice era of Classical music to the 21st century. Chord progressions are the foundation of popular music styles, traditional music, as well as genres such as blues and jazz. In these genres, chord progressions are the defining feature on which melody and rhythm are built.
A chord, in music, is any harmonic set of pitches consisting of multiple notes that are sounded simultaneously, or nearly so. For many practical and theoretical purposes, arpeggios and other types of broken chords may also be considered as chords in the right musical context.
In music, modulation is the change from one tonality to another. This may or may not be accompanied by a change in key signature. Modulations articulate or create the structure or form of many pieces, as well as add interest. Treatment of a chord as the tonic for less than a phrase is considered tonicization.
Modulation is the essential part of the art. Without it there is little music, for a piece derives its true beauty not from the large number of fixed modes which it embraces but rather from the subtle fabric of its modulation.
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.
In Western music and music theory, diminution has four distinct meanings. Diminution may be a form of embellishment in which a long note is divided into a series of shorter, usually melodic, values. Diminution may also be the compositional device where a melody, theme or motif is presented in shorter note-values than were previously used. Diminution is also the term for the proportional shortening of the value of individual note-shapes in mensural notation, either by coloration or by a sign of proportion. A minor or perfect interval that is narrowed by a chromatic semitone is a diminished interval, and the process may be referred to as diminution.
In music theory, a diminished triad 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 symbols "dim", "o", "m♭5", or "MI(♭5)". However, in most popular-music chord books, the symbol "dim" and "o" represents a diminished seventh chord, which in some modern jazz books and music theory books is represented by the "dim7" or "o7" symbols.
In music, the submediant is the sixth degree of a diatonic scale. The submediant is named thus because it is halfway between the tonic and the subdominant or because its position below the tonic is symmetrical to that of the mediant above.
In music or music theory, a thirteenth is the note thirteen scale degrees from the root of a chord and also the interval between the root and the thirteenth. The thirteenth is most commonly major or minor.
Chromaticism is a compositional technique interspersing the primary diatonic pitches and chords with other pitches of the chromatic scale. In simple terms, within each octave, diatonic music uses only seven different notes, rather than the twelve available on a standard piano keyboard. Music is chromatic when it uses more than just these seven notes.
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:
The diminished seventh chord is a four-note chord composed of a root note, together with a minor third, a diminished fifth, and a diminished seventh above the root:. For example, the diminished seventh chord built on B, commonly written as Bo7, has pitches B-D-F-A♭:
In music theory, chord substitution is the technique of using a chord in place of another in a progression of chords, or a chord progression. Much of the European classical repertoire and the vast majority of blues, jazz and rock music songs are based on chord progressions. "A chord substitution occurs when a chord is replaced by another that is made to function like the original. Usually substituted chords possess two pitches in common with the triad that they are replacing."
In music, an augmented sixth is an interval produced by widening a major sixth by a chromatic semitone. For instance, the interval from C to A is a major sixth, nine semitones wide, and both the intervals from C♭ to A, and from C to A♯ are augmented sixths, spanning ten semitones. Being augmented, it is considered a dissonant interval.
In music theory, the half-diminished seventh chord is a seventh chord composed of a root note, together with a minor third, a diminished fifth, and a minor seventh. For example, the half-diminished seventh chord built on B, commonly written as Bm7(♭5), or Bø7, has pitches B-D-F-A:
In music, the dominant is the fifth scale degree of the diatonic scale. It is called the dominant because it is second in importance to the first scale degree, the tonic. In the movable do solfège system, the dominant note is sung as "So(l)".
In music, a rewrite rule is a recursive generative grammar, which creates a chord progression from another.
In music theory, a nondominant seventh chord is both a diatonic chord and a seventh chord, but it does not possess dominant function, and thus it is not a dominant seventh chord.
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:
Cited in Baker, Robert M. (2005)
Cited in Middleton (1990)
| Musical form | |
|---|---|
| Origins | |
| Regional styles | |
| Subgenres | |
| Fusion genres | |
| Lists | |
