In 1928, George and Ira Gershwin
composed the iconic song “I Got Rhythm.” In
the years following, the harmonic structure of
this timeless classic has become the backbone
of countless songs written and/or performed
by such varied artists as Charlie
Parker, Kenny Rogers, and even the Beatles.
Not only has “I Got Rhythm” been
recorded by a plethora of vocalists and
instrumentalists, it has also become a
measure of a musician’s improvisational
skills. A big reason for this is the I-VI-II-V (or
III-VI-II-V) progression in the A-sections of
the tune. Because these harmonies are
in so many standard tunes (jazz, pop,
rock, gospel, and country), if you can
improvise over “Rhythm Changes,” you can
improvise over a lot of other tunes in a
variety of styles.
The structure of “Rhythm Changes” is
the 32-bar AABA form, with each section
consisting of eight measures. The A-sections
contain the I-VI-II-V progression. The
B-section consists of dominant seventh
chords starting on the III7, moving in a
cycle of fourths. To hone your skills, isolate
the sections, and practice playing on
each of them before putting the parts back
together. Then, you’ll be ready to use these
devices on dozens of tunes!
Ex. 1. The I-VI-II-V progression in the key of Bb. This progression is repeated in the first four measures of “I Got Rhythm” in the A sections. Although the original was in
the key of Db (as were many songs composed in that era), the most common key for “Rhythm Changes” these days is Bb.
Click for audio.
Ex. 2. The melody of “I Got Rhythm” is drawn from the major pentatonic scale (1, 2, 3, 5, 6). The bulk of the melody in the A-sections uses four of the five notes of that
scale. This right hand improvisation uses the Bb major pentatonic scale, along with the “blue” notes b3 and b7. The b7 is introduced in measure 5, to reinforce the
modulation to the IV chord, a pivotal harmonic movement in “Rhythm Changes.” Notice the subtle difference between the first and second endings — a good way of keeping
your place in this AABA form. Click for audio.
Ex. 3. The first half of the B-section starts on the III7 and moves up the cycle of fourths. Left hand voicings consist of guide tones (thirds and sevenths) and roots. The
right hand is using the dominant diminished scale, always a good choice for use on dominant sevenths. Click for audio.
Ex. 4. In the second half of the bridge, we’re preceding the dominant seventh chords by minor seventh chords (often called “II-V’ing”). This gives us more chords to play
on, and adds some extra movement, while retaining the underlying harmonic intent. The right hand lines outline the minor seventh chords with some added chromatic
tones. Notice that the seventh of the minor chord resolves to the third of the dominant seventh chord. Click for audio.
Ex. 5. The final A-section. By outlining the chords in the right hand, the tune almost plays itself. Along with a few choice chromatic tones, you can weave an eighth-note
improvisation over the moving changes quite nicely. The diminished chords are common substitutions for the dominant sevenths in the first two measures. For dramatic
effect, we end on the tritone substitution of E7#11. Click for audio.
Jazz pianist, composer, and longtime Keyboard contributor Andy LaVerne has played and recorded with such renowned artists as Frank Sinatra, Stan Getz, and Chick Corea. A professor of jazz piano at the Hartt School of Music at the University of Hartford, his latest CD is Live at the Kitano, Vol. 1. Visit him at andylaverne.com.