Twelve-bar blues

Typical boogie woogie bassline on twelve-bar blues progression in C, chord roots in red.  Play 

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.

The blues can be played in any key. Mastery of the blues and rhythm changes are "critical elements for building a jazz repertoire".^[1]

Structure

The most common or standard twelve-bar blues progressions variations, in C. (Benward & Saker, 2003, p. 186)  Play A ,  B ,  C ,  D , and  E  as boogie woogie basslines. For example, Robert Johnson's "Sweet Home Chicago" (1936) uses A.

In the key of C, one basic blues progression (E from above) is as follows.^[2] (For the most commonly used patterns see the section "Variations", below.)

Chords may be also represented by a few different notation systems such as sheet music and electronic music. A basic example of the progression would look like this, using T to indicate the tonic, S for the subdominant, and D for the dominant, and representing one chord. In Roman numeral analysis the tonic is called the I, the sub-dominant the IV, and the dominant the V. (These three chords are the basis of thousands of pop songs, which thus often have a blues sound even without using the classical twelve-bar form.)

Using said notations, the chord progression outlined above can be represented as follows.^[3]

The first line takes four bars, as do the remaining two lines, for a total of twelve bars. However, the vocal or lead phrases, though they often come in threes, do not coincide with the above three lines or sections. This overlap between the grouping of the accompaniment and the vocal is part of what creates interest in the twelve bar blues.

Variations

"W.C. Handy, 'the Father of the Blues', codified this blues form to help musicians communicate chord changes."^[4] Many variations are possible. The length of sections may be varied to create eight-bar blues or sixteen-bar blues.

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:^[5]

I	I	I	I
IV	IV	I	I
V	IV	I	I

 Play 

The common quick to four or quick-change (quick four^[6]) variation uses the subdominant chord in the second bar:

I IV I I IV IV I I V IV I I

These variations are not mutually exclusive; the rules for generating them may be combined with one another (or with others not listed) to generate more complex variations.

Seventh chords 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:

Using a seventh chord

I	IV	I	I7
IV	IV7	I	I7
V	IV	I	V7

When the last bar contains the dominant, that bar may be called a turnaround; otherwise the last four measures is the blues turnaround.

Basic jazz blues progression

I7	IV7 ♯IVo7	I7	v7 I7
IV7	♯IVo7	I7	iii7 VI7
ii7	V7	iii7 VI7	II7 V7

 Play 

In jazz, twelve-bar blues progressions are expanded with moving substitutions and chordal variations. The cadence (or last four measures) uniquely leads to the root by perfect intervals of fourths.

Bop V/ii arpeggio, in second measure, upwards from third (C♯) to ninth (B♭): A^7♭9(Spitzer 2001, 62) the dominant of D minor (ii in C major)  Play .

The Bebop blues:^[7]

Bebop blues

I7	IV7	I7	v7 I7
IV7	♯IVo7	I7	V/ii♭9
ii7	V7	I7 V/ii♭9	ii7 V7

 Play 

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.^[7] "It is a bop soloist's cliche to arpeggiate this chord [A^7♭9 (V/ii = VI^7♭9)] from the 3 up to the ♭9."^[7]

Minor blues (Spitzer 2001, p. 63)

i7	i7	i7	i7
iv7	iv7	i7	i7
♭VI7	V7	i7	i7

 Play 

There are also minor twelve-bar blues, such as John Coltrane's "Equinox" and "Mr. P.C.",^[8] and "Why Don't You Do Right?", made famous by Lil Green with Big Bill Broonzy and then Peggy Lee with the Benny Goodman Orchestra. The chord on the fifth scale degree may be major (V⁷) or minor (v⁷), in which case it fits a dorian scale along with the minor i⁷ and iv⁷ chords, creating a modal feeling.^[8] Major and minor can also be mixed together, a signature characteristic of the music of Charles Brown.^[9]

While the blues is most often considered to be in sectional strophic form with a verse-chorus pattern, it may also be considered as an extension of the variational chaconne procedure. Van der Merwe (1989) considers it developed in part specifically from the American Gregory Walker, though the conventional account would consider hymns to have provided the repeating chord progression or harmonic formulae of the blues.^[10]

References

Sources

• Benward, Bruce, and Marilyn Nadine Saker (2003). Music: In Theory and Practice, Vol. I, seventh edition. Boston: McGraw-Hill. ISBN 978-0-07-294262-0.
• Covach, John. "Form in Rock Music: A Primer", in Stein, Deborah (2005). Engaging Music: Essays in Music Analysis. New York: Oxford University Press. ISBN 0-19-517010-5.
• Doll, Christopher (2009). "Transformation in Rock Harmony: An Explanatory Strategy". Gamut (2): 1–44.
• Jackson, Fruteland (2002). Beginning Delta Blues Guitar. Alfred Publishing. ISBN 978-0-7390-3006-6.
• Gerow, Maurice and Tanner, Paul (1984). A Study of Jazz, Dubuque, Iowa: William C. Brown Publishers, p. 37, cited in Baker, Robert M. (2005).
• Greene, Ted (1971/1992). Chord Chemistry: For Guitar. Alfred Music. ISBN 9781457455292.
• Kernfeld, Barry, ed. (2007). "Blues progression". The New Grove Dictionary of Jazz;. 2nd Edition. Oxford, UK: Oxford University Press.
• Middleton, Richard (1990/2002). Studying Popular Music. Philadelphia: Open University Press. ISBN 0-335-15275-9.
• National Guitar Workshop (2003). Electric Bass for Guitarists. Alfred Publishing. ISBN 0-7390-3335-2.
• Spitzer, Peter (2001). Jazz Theory Handbook. Mel Bay. ISBN 978-0-7866-5328-7.
• Thomas, John (2002). Voice Leading for Guitar: Moving Through the Changes. Berklee Press. ISBN 0-634-01655-5.
• van der Merwe, Peter (1989). Origins of the Popular Style. Oxford: Clarendon Press. ISBN 0-19-316121-4. Cited in Middleton (1990).