VII. Jazz

Blues harmony

Bryn Hughes and Megan Lavengood

Key Takeaways

  • Blues harmony differs from tonal and jazz harmony in a number of important ways, especially in the treatment of the .
  • In a standard 12-bar blues, all chords are .
  • The blues is a that can have many alterations without ceasing to qualify as “a blues.”
  • Common variations on the 12-bar blues are the , the , and the .
  • The jazz blues blends jazz and blues harmonic languages together.

The blues is an extraordinarily important genre in U.S. popular music. Not only is the tradition itself very old, with roots reaching back to the music of enslaved African-Americans, but it continues to exert influence on 21st-century popular music.

The documentation on the history of the blues is quite limited due to its age, but the earliest blues songs existed in the late 1800s, and it seems to have grown out from earlier African-American musical styles, such as field hollers and work songs, as well as and rhythmic characteristics of West African music. In this sense, although jazz musicians very frequently play the blues, the blues as a tradition has distinct origins from jazz. Jazz developed first in New Orleans through a mix of African, Caribbean, and European influences. The result of this distinction is that many of the truisms of jazz or tonal music do not hold true in the blues. Among the biggest harmonic differences are that

  • can have any (tonic, dominant, or subdominant)
  • provide structural closure, instead of
  • major and minor thirds are freely mixed together, and even used simultaneously (sometimes written in as a major/dominant chord with a ♯9 extension)

This chapter introduces some of the most common forms of the blues encountered in the 20th and 21st centuries.

12-bar blues

The blues is a : a frame of reference for understanding lots of different chord progressions. Blues progressions can all be understood as outgrowths from a basic prototype.

The is composed of three (typically) four-bar phrases. A major difference between the blues and more traditionally tonal music is that it emphasizes  instead of . At its most basic, the harmony progresses as shown in Example 1:

  1. The first phrase is entirely tonic harmony (I).
  2. The second phrase contains two bars of subdominant (IV) and two bars of tonic (I).
  3. The final phrase begins with one bar of dominant (V) followed by one bar of subdominant (IV) and two bars of tonic (I).
  4. All chords are dominant 7th chords and do not fit into a single key.

Example 1. A basic twelve-bar blues has four measures of I for its first phrase, two measures of IV and two measures of I for its second phrase, and the final phrase has a bar of V, a bar of IV, and then two bars of I. All chords are dominant sevenths.

This is the simplest version of the 12-bar blues, but innumerable variations exist upon these changes. One of the most common additions is that the second bar may move to IV, then return to I in the third bar. Another especially common trick is to employ some type of in the final bar or two of the progression, from something as simple as a V7 chord to a full III–VI–II–V progression. It can be difficult to find a blues tune that doesn’t make some alteration from the basic form shown in Example 1. “You Can’t Do That” by The Beatles (1964) is nearly the same, but it does add a V chord in the final bar as a turnaround.

notation of 16-bar blues
Example 2. 16-bar blues.

Closely related is the , which is composed of four 4-bar phrases, usually two iterations of tonic, followed by subdominant and dominant (Example 2). “Hoochie Coochie Man” by Muddy Waters (1954) is one example of a 16-bar blues. Notice that the final phrase may or may not end with a . The 16-bar blues is not as common as the 12-bar blues, but has somewhat heightened frequency in blues-based rock music.

Most commonly, the blues is in “major” (which, in this context, simply means that the tonic harmony has a major 3rd above it—many pitches in a major blues fall outside the major scale). But another common variation on the blues is a . In a minor blues, the i and iv chords are minor sevenths instead of dominant sevenths; the V stays dominant. Because the motion from the major V to the minor iv can sound anticlimactic, the minor blues also typically replaces the V–IV–I motion in the third phrase with a ii–V–I (Example 3).

Example 3. The minor blues uses minor seventh chords on the i and iv chords, and replaces the V–IV–I cadence with a ii–V–I cadence.

Jazz blues

As mentioned in the introduction to this chapter, the blues treats harmony differently from jazz, and one of the large differences is the reliance upon rather than cadences. The is a variant of the 12-bar blues that mitigates this somewhat by adding several ii–V progressions to the blues.

Like the 12-bar blues, the jazz blues is composed of three 4-bar phrases. A basic version of the jazz blues is presented in Example 3.

Notice that the jazz blues mixes typical blues harmony (i.e., the use of non-V dominant seventh chords and plagal resolutions) with jazz harmonic schemas: specifically, it uses ii–Vs and . In the eighth bar, instead of remaining on tonic, there is an applied ii–V that leads to the ii chord in bar 9. And in the third phrase, the V–IV–I of the standard blues is replaced with a ii–V–I more common to jazz.

Example 4. The jazz blues adds ii–V progressions, replacing structural plagal cadences.

One recording that performs the blues this way is the Lincoln Center Jazz Orchestra performing Duke Ellington’s “C Jam Blues.” This is easiest to hear during the solo sections, however not every repetition of this blues contains every chord shown in Example 4.

Examples of variations

The blues can be varied extensively, yet still qualify as the blues. The chapter’s Spotify playlist goes through several tracks that have some slight variations on the schemas outlined above.

  • “Runaway Blues” by Ma Rainey (1928) uses a IV in the first tonic phrase, and also embellishes the final V with an applied V/V.
  • “Empty Bed Blues, Pt. 1” by Bessie Smith (1928) follows a basic 12-bar blues, but precedes most new harmonies with a tonicizing ii–V progression.
  • “Surfin’ USA” by the Beach Boys (1963) presents a 16-bar blues, but he two first phrases each begin with two bars of V before two bars of I.
  • “The Thrill is Gone” as recorded by B.B. King (1970) is in minor, and replaces the ii–V of the final phrase with ♭VI–V.

Musicians who have developed a familiarity with the blues will have no trouble recognizing the blues in a tune even with these, and more, variations.

  1. Worksheet on 12-bar blues (.pdf, .mscz). Asks students to write basic and jazz 12-bar blues progressions, voiced and unvoiced, and to analyze altered blues progressions. Worksheet playlist

Media Attributions

  • 16barblues


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