When George and Ira Gershwin first wrote “I Got Rhythm” for the 1930 musical Girl Crazy, they couldn’t possibly have imagined the effect that this catchy song would have on American popular music. It soon became not just one of the most celebrated tunes in the Great American Songbook, the body of work composed for musicals and films from the 1920s through the ‘50s, but one of the most common vehicles for jazz improvisation.
Jazz musicians first began writing new melodies over the chord changes to “I Got Rhythm” in order to circumvent copyright fees. A great number of pieces in the jazz canon—Duke Ellington’s “Cotton Tail,” Thelonious Monk’s “Rhythm-a-Ning,” and Charlie Parker’s “Moose the Mooche,” to name just a few—are based on this progression, which is known in the jazz vernacular as rhythm changes.
As with any chord progression, rhythm changes lends itself to an infinite range of treatments. Acoustic Guitar reached out to an eclectic group of five jazz guitarists—Mimi Fox, Matt Munisteri, and Frank Vignola, and contributing writers Ron Jackson and Sean McGowan—to give you a good sense of the possibilities inherent to this all-important form.
Rhythm changes occupies the classic 32-bar AABA song form, in which each section is eight measures long. It was originally composed in Db major, but jazz musicians often play it in Bb. The form is shown in the latter key in its most basic form in Example 1. In the A section, the harmonic rhythm is mostly two chords per measure, with a I–VI–ii–V progression in the first four measures.
The B section, in contrast, has a harmonic rhythm of one chord for every two bars. Its four dominant-seventh chords—in the key of Bb, D7, G7, C7, and F7—travel counterclockwise of the circle of fifths (a geometrical depiction of the relationship between key signatures). The F7 leads smoothly back to the first chord of the A section, Bb, as these two chords have a V–I relationship.
Each of our guitarists takes a different tack to rhythm changes. Due to space restrictions, only five A sections are included here, but you can see the players negotiating the entire form and download the full notation at acousticguitar.com.
For his example, Frank Vignola—a versatile jazz guitarist who has worked with everyone from Wynton Marsalis to Madonna—plays rhythm changes in Bb using single notes exclusively. As shown in Example 2, he solos in a simple but highly effective way. He focuses largely on chord tones—the first four notes are simply the roots of the first four chords; bar 5 is built around the thirds of Cm7 and F7 (Eb and A, respectively).
Note the generous use of rests in Vignola’s passage, giving the music plenty of room to breathe, as well as the syncopation and rhythmic displacement at work. Many of the notes fall on the “ands” of beats, and some of the notes are situated in unexpected places. Instead of beat 1 of bar 1, for instance, the first note, Bb, lands on beat 2.
Ron Jackson, an ace sideman with collaborators like pianist Benny Green, and also a bandleader, takes a bebop-oriented approach in his chorus, excerpted in Example 3. His lines imply some classic chord substitutions. For instance, in bar 2 he plays notes belonging to a C#dim7 chord, rather than an F7, which smoothly bridges the Cm7 chord that precedes it and the Dm7 in the following measure. Similarly, in the last two bars he uses notes from a Dbm7 chord to connect Dm7 and Dbm7.
In contrast to Vignola’s A section, Jackson’s is dense—there are only two quarter-note rests in eight bars of music. This near-constant velocity certainly has its place in soloing on rhythm changes, or any jazz form for that matter. It’s a great way to build excitement.
Sean McGowan is a music professor at the University of Colorado Denver and the author of an upcoming Acoustic Guitar comprehensive jazz method. He also goes for velocity in his example. But he does something altogether different, harmonically speaking. Instead of Bb, he plays in the key of G (Example 4), and rather than work with the chord changes, he treats the whole section as one big G7 chord—a strategy often employed by modern jazz musicians.
Within this context, McGowan demonstrates some interesting ideas. He mixes up bluesy phrases with outside lines—that is, those harmonically distant from the chord. In bar 3, starting on beat 2, he plays a Db–Eb–Fn–Ab tetrachord (four-note group), which highlights altered notes of the G7 chord. He then transposes the whole tetrachord up a tritone (three whole steps; bar 5, beats 1 and 2), notes that are “inside” and less tense, before transposing it up another tritone (or an octave above the original tetrachord).
The previous examples have all been strictly melodic, but the last two, by Mimi Fox and Matt Munisteri, throw some chords into the mix. In her A section, Fox, who leads the San Francisco String trio, among other projects, establishes a cool walking bass line with chordal accents—see Example 5.
For the bass line, Fox tends to play root notes on beats 1 and 3, and non-chord tones elsewhere. She sometimes pulls off to an open string, for both textural effect and rhythmic drive, not unlike an upright bassist. In the first four bars, the chords reflect common extensions used by jazz guitarists (9, b13, etc.), in finger-friendly, three-note grips.
In the second four bars, Fox manages to throw in some melodic action on the upper strings, creating the aural impression of more than one instrument being played: the ultimate goal for solo jazz guitar in rhythm changes or any other context.
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Eclectic guitarist and singer-songwriter Matt Munisteri channels jazz guitar pioneers like Eddie Lang in his take on rhythm changes (Example 6). Munisteri plays a bunch of three-note voicings in a lively chord-melody-style improvisation. Notice the tidy ways in which he gets from chord to chord. For instance, in bar 4, to move between Cm7 and the surprise chord of F#7, he shifts the highest voice down a half step, to F# from G, and the middle voice in the opposite direction, up a half step, to En from Eb.
Check out the video to see how smoothly and effortlessly Munisteri appears to shift between the different chord grips. His improv really sounds like singing—an effect you should always strive for, whether you’re playing rhythm changes or guitar in general.