The Blues in Jazz: Using the Classic 12-Bar Form to Learn Bebop Improv

In a sense, the genres of jazz and blues grew up together throughout various regions of America in the 20th century. The blues has roots in the antebellum South. Via itinerant musicians at first and later records and radio, it spread throughout the west to Texas and beyond, northeast to Memphis and the Carolinas, and due north to Chicago and Detroit during the Great Migration of African Americans out of the rural South to the industrialized cities of the North.

There is a very thin veil between early New Orleans jazz styles and blues. In fact, early jazz pioneers such as Louis Armstrong and Sidney Bechet worked and recorded with popular classic blues singers. Whether talking about song form, chord progressions, lyrical themes, melodic and rhythmic vocabulary, or just the general feeling, the blues is an essential ingredient to just about every American style of music, including jazz, country, rock, soul, etc.

If you listen to the jump swing of Louis Jordan, the urban West Coast blues of T-Bone Walker, the early bebop/swing style of Charlie Christian, and the western swing of Eldon Shamblin and Junior Barnard with Bob Wills and His Texas Playboys, you’ll hear a lot more similarities than differences. The common thread that connects them all? The blues.

In this lesson, you’ll explore comping and soloing strategies over a standard 12-bar jazz blues progression, as well as chord substitutions and variations such as the minor blues form and Charlie Parker’s “Bird Blues.” Once you are well acquainted with these common blues forms, you’ll be ready to hit those jam sessions.

Standard Jazz Blues Progressions

In contemporary jazz, a blues form typically means a repeating 12-bar progression—often in a horn-friendly key like F or Bb—with standard chord changes and common substitutions. There are many different blues-based heads, or melodies, in the jazz canon: standards such as Charlie Parker’s “Au Privave” and “Billie’s Bounce,” Thelonious Monk’s “Straight, No Chaser,” and Clifford Brown’s “Sandu.”

Example 1 shows the standard chord changes for a 12-bar blues in the key of F. In the first four bars, the chords are almost identical to a traditional blues. The I chord is followed by the IV chord in the second bar, then back to the I in the third. As in a traditional blues progression, both the I and IV chords are dominant in quality. One slight variation is in bar 4: There is a ii–V move that sets up the IV7 (Bb7) chord in bar 5. The ii–V change is ubiquitous in jazz, and the blues progression is no exception. In this case, since you’re approaching a Bb7 chord, the Cm7–F7 leading up to that measure is called a ii–V of IV (Cm7 = ii and F7 = V of Bb7).

A defining characteristic of the blues is the IV7 on the fifth bar (or first bar of the second phrase of the tune). In measure 6, the root of the IV chord moves up a half step to create a colorful #ivdim7 chord (Bdim7), which is followed by a return to the tonic (F7).

In bar 8, there’s another ii–V, this time approaching the iim7 (Gm7) chord in bar 9 (beginning of the last four-bar phrase). The ii–V of Gm7 is Am7–D7. Note that the Am7 chord features an E natural and the D7 features an F#, neither of which are found in F minor pentatonic or blues scales.

Also notice that whenever there is dominant-to-tonic (V7–I) movement, such as in measures 4–5 and 8–9, the V7 chord can feature altered extensions to create tension and resolution. In Ex. 1, the F7 in the fourth measure features both the #9 and b9 extensions (creating some inner line movement), and the D7 in bar 8 includes a b9. Bars 9–10 include a ii–V (Gm7–C7), resolving to the tonic (F7) and ending with a quick turnaround (F7–D7–Gm7–C7). The turnaround is essential in all styles of blues, and whether via a riff, signature lick, or common chord sequence, it signifies the end of one form and turns around to the start of another.

Blues Comping Strategies

When comping through a blues progression, you can use syncopated rhythms to create a strong swing feel. Also, many guitarists opt for a full chordal sound by playing voicings on the middle four strings, as in Example 2. This exercise is built from a Charleston rhythm in the first bar, as well as the rhythmic elements of anticipation (the Bb7 chord in bars 1 and 4) and delayed attack (the F7 in measure 3 and Cm7 in 4).

Also, notice the use of colorful notes: The F7 and Bb7 chords include ninth and 13th extensions, the Cm7 uses a ninth, and the F7 in bar 4 highlights altered-ninth extensions as it approaches the Bb7 chord in the following measure, creating a V7–I type of connection.

Example 3 continues through the F blues progression from bar 5, offering some suggested voicings and rhythms to play behind a soloist or even as a chord solo. Again, notice how extensions are used in the chord voicings to create color, and try to visualize the root of each chord, even though it’s not a part of the voicing. (Remember, the bassist will usually handle the root in a group setting.)

The guide tones, however, are always present. They define the sound of each chord, while the extensions create tension and resolution from altered to unaltered voicings, as in the D7alt-to-Gm7 cadence and the chordal turnaround in the last two measures. This example also shows a chromatic approach of an E7 up a half step to the tonic F7 chord.

You can approach any of these chords from a half step above or below, and dominant-seventh chords tend to sound the best. They provide a really nice chromatic effect that lends itself well to the sound of the blues. You can also substitute a dominant-seventh chord for the iim7 chord, in this case a G7 instead of Gm7, as shown in the penultimate measure.

There are a few common substitutions that guitarists and pianists use when comping. In measure 6 of the blues form, you can substitute the diminished-seventh chord (Bdim7) with a dominant seventh on the b7 of the key (Eb7). That way, you can approach the tonic (F7) quite naturally (Example 4).

Measures 7–8 feature additional descending and ascending chords that connect to the iim7 in bar 9, as shown in Examples 5a–b. Each chord in the turnaround (bars 11–12) can be substituted with a dominant-seventh chord a tritone away (Example 6). The original turnaround, F7–D7–G7–C7, is now replaced with F7–Ab7–Db7–Gb7.

This device, known as a tritone substitution, works because two dominant-seventh chords a tritone apart share the same guide tones. As seen in Example 7, the third of one becomes the flatted seventh of the other, and vice versa. For example, the guide tones of a C7 chord are E (3) and Bb(b7), which, oppositely, happen to be the third (Bb) and flatted seventh (Fb/E) of a Gb7 chord. Notice also that the guide tones are a tritone apart within the chord voicing.

Soloing Strategies on Blues

There are a number of different ways to approach soloing over a blues. Harmonically speaking, bebop musicians tend to think vertically, outlining each individual chord and often adding substitutions. However, since it is a blues, soloists also employ pentatonic and blues scales to great effect. Combine these strategies with swing rhythms, motivic development, repetition, emotion, and so forth, and you have the recipe for a powerful blues statement in a jazz context.

Let’s explore the first four measures of an F blues with a few of these different strategies. Example 8 shows a vertical approach to playing over the chords using arpeggios and chord tones. Notice how the first bar features the ninth (G) of the F7 chord (like the F9 voicing in Ex. 1), while the fourth bar features a flatted-ninth color tone, which sets up some nice tension to be resolved in the following Bb7 chord. You can essentially use the same harmonic devices and approaches whether you are comping or soloing.

Example 9 takes the same melodic line and adds some chromatic activity, which is an essential characteristic of bebop blues. The first two bars utilize chromaticism in the line itself; bar 1 contains a descending chromatic line working from the C down to Ab, and the following measure features a double chromatic enclosure (neighbor tones setting up the approach note from a half step above and below) within the triplet figure.

In this case, you’re setting up the chord-tone F in measure 3 by playing chromatic notes above and below (Gb and E). This type of ornamental turn is found in many styles of music; the highly chromatic nature of this approach is comfortably at home in the jazz blues.

Ex. 9 culminates in a chromatic approach to the chord: Instead of outlining the Cm7–F7–Bb7 progression, you can approach the Bb7 chord chromatically by outlining a dominant-seventh chord a half step above, resulting in a progression of Cm7–B7–Bb7. The most effective way to do this is by playing a triad or seventh-chord arpeggio on the chord of substitution.

Another device popular with guitarists is the concept of playing minor lines, arpeggios, and patterns built on the fifth of a chord. For example, over an F7 chord you can think and play C minor; over Bb7, use F minor, and so on. Generally speaking, minor-seventh arpeggios and minor-pentatonic lines sound best in this application.

You’ll find examples of this approach throughout masterful blues solos by Wes Montgomery, George Benson, and Pat Martino. The first three measures of Example 10 superimpose a Cm chord over an F7, Fm over Bb7, and Cm over F7, respectively. You can also use this concept over minor-seventh chords—the Cm7 chord in measure 4 includes a G minor arpeggio. Combine it with a chromatic approach: The following F7alt chord features an F# minor arpeggio, which is built on the fifth of a B7 chord—the tritone substitution of F7 and the chromatic approach to Bb7.

Of course, when playing a jazz blues, you can also play lines derived from the blues scale, as shown in Example 11. Even though you’re using a blues scale, the harmonies are effectively outlined through an emphasis on chord tones on the strong beats of each measure—one of the hallmarks of a coherent jazz-blues solo.

Essential Listening

Here’s a handful of great tunes exploring an intersection of jazz and the blues:

• T-Bone Walker “They Call It Stormy Monday” from Greatest Hits
• Eldon Shamblin & Junior Barnard “Milk Cow Blues” from Bob Wills & His Texas Playboys Basin Street Blues
• Charlie Christian “Grand Slam” from The Genius of the Electric Guitar
• Wes Montgomery “No Blues” from Smokin’ at the Half Note
• George Benson “Billie’s Bounce” from Giblet Gravy
• Pat Martino “A Blues for Mickey-O” from El Hombre