âLet’s play the rhythm! It’s a phrase jazz musicians often hear at jam sessions or on the bandstand. This means: “Let’s improvise on the harmonic structure of the great American classic I Got Rhythm”. Jazz musicians have used the form and harmony of “rhythm changes” (the jazz term for the harmonic structure of I have rhythm) for years as the basis for new jazz melodies and improvisations. The most enduring and frequently played forms of jazz are twelve bar blues and “rhythm changes.”
In this article, we’ll use walking basslines to explore some of the many harmonic variations of ârhythm changesâ.
I have rhythm was written by George and Ira Gershwin in 1930 and has found its place in the series Crazy girl. After Ethel Merman’s performances in the original Broadway production, jazz musicians of the day quickly took up the song’s melody and harmony as a vehicle for improvisation. In 1938, clarinetist Benny Goodman recorded one of the most famous versions of I have rhythm, starring Gene Krupa, Teddy Wilson and Lionel Hampton, released on Sony under the name Jazz concert at Carnegie Hall.
The song’s most famous recording as a bass function comes from a concert at New York’s Town Hall in 1945. Leroy ‘Slam’ Stewart and tenor saxophonist Don Byas perform an incredible duet on the melody. Slam weaves his way into a two-beat bassline below Byas’ solo, then delivers his own incredible solo, with his signature vocals, in unison, an octave above the bowed bass.
The most enduring and frequently played forms of jazz are twelve bar blues and “rhythm changes.”
The performance is hard to find on CD, but is currently available in most digital music stores. In the era of swing and bebop, many jazzers used the harmonic structure of the Gershwin classic as the basis for new melodies. When jazz musicians refer to “rhythm changes” they are referring to the harmony or progression of chords and the form of the original song. A jazz melody based on the harmony of a different song in this way is called a counterfeit.
Songs like Duke Ellington Cotton tail, Lester Young Lester jumps In and Nat King Cole’s To sort out and Fly right are all classic swing songs based on “rhythm changes”. Anthropology, Moose the Mooche and Steeplechase are some of the famous counterfeits of “rhythm changes” composed by alto saxophonist Charlie Parker during the bebop era. Other notable fakes of ‘rhythm changes’ include Sonny Rollins Oleo, Thelonious Monk’s Rhythm-A-Ning, and the cartoon theme Meet the Flintstones by Hoyt Curtin.
Playing harmony over “rhythm changes” has become one of the ultimate tests of jazz mastery. It has provided a common canvas for the last 80 years of jazz history, with everyone from Duke Ellington to Pat Metheny painting part of the picture.
NUTS AND BOLTS
What makes “rhythm changes” such a solid foundation for improvisation? What makes the game so fun? The chord progression is simple enough that a musician can successfully improvise over the structure using the B flat, C, D, F, G pentatonic scale. The more adventurous improviser can add substitutions and reversals, techniques that we will explore here, to create the ever more complicated harmony.
The original form is AABA, four eight-bar phrases. A two bar tag is added in the original composition, with a repeat of the âWho could ask for something moreâ line, making the original form 34 bars long. Almost all jazz counterfeits omit the label, making “rhythm changes” a basic 32 bar form. In its simplest variation, the first eight bars of “rhythm changes” can be played as in Example 1.
Jazz players usually choose to add chords to spruce up the basic harmony. There are countless variations of “rhythm changes”, with many subtle differences. Example 2 shows the entire shape with some typical variations. In bars 1 and 2, the simple option of example 1 is extended to a recovery.
As the word suggests, a turnaround brings a progression of chords around a cycle and returns to a starting point. The basic progression I to V7 in Example 1 (B # maj6 to F7) is extended to I, VI7, II7, V7 (B # maj6, G7, Cmin7, F7). In measure 3, the turnaround starts on III7 (Dmin7), which is similar to B # maj6 in sound. In bars 3 and 4, the turnaround leads to the B # 7 chord in bar 5. There are many options for the turns in the first four bars of “rhythm changes,” and jazz players often change the tone. spontaneous chord progression when improvising.
THE VARIETY IS THE SPICE
How do you know when to use variations of “rhythm changes”? This spontaneous re-harmonization on the ground is not as mysterious as it seems. Jazz musicians improvise according to basic structures, but often add additional chords or generalize groups of chords into a single sound. When a player experiences several harmonic variations of “rhythm changes”, then it is sometimes second nature to change or embellish the chord progression instinctively in the heat of improvisation. An important aspect that helps jazz musicians choose variations spontaneously is a common repertoire of historically important jazz songs.
For example, that of Miles Davis The theme and Sonny Stitt The eternal triangle are both based on “rhythm changes”, but the chord progression in the B sections of the two songs is different. As experienced jazz musicians have heard both pieces a lot (they are classics), it is easy to follow a soloist when he goes from one variation to another during an improvisation. It sounds great when all of the musicians at the bandstand are always playing the same harmonic variations, but it’s not always imperative.
Sometimes a soloist (or a pianist or bassist) will add a variation that other players don’t hear, or choose to pick up. What happens when a player improvises on a different chord set than the other players? If players improvise together and describe different variations of the same underlying structure, the sound will still be consistent. For example, if, as in Example 3, the pianist plays B # maj6, Gmin7, Cmin7, F7 in the first two bars, while the bassist plays B # maj6, F7, the result is still harmonious.
They’ll both most likely land on a Dmin7 or B # maj6 chord on the first beat of bar 3, so the turnaround – even if they play two different chord sequences – will still be full and compelling. Another attractive aspect of “rhythm changes” is the bluesy feeling that occurs in bars 5 and 6. The movement of the I7 chord (B # 7) in bar 5, to the IV chord (E # maj6 or E # 7) in measure 6, has a feeling similar to a blues progression. Bar 6, however, presents a tricky option: the chord on beats 3 and 4 can be either an Edim7 or an E # min6. It is an important place for the bassist!
Note that in Example 2, bar 6, the Edim7 is used, and in bar 14, the alternative choice is: E # min6. Most jazz melodies favor one chord progression or the other, and most jazz players will stick to a variation of this measure throughout an improvisation.
The original Gershwin I have rhythm the melody is best harmonized using E # 6 to E # min6 in measure 6. The B section (the third eight-bar phrase, also called the bridge) of the ârhythm changesâ begins on the III7 (D7) chord , and moves through the cycle of fifths (D7, G7, C7, F7) eventually resolving to B # maj6 to bring up the final section A. There are many popular variations of the bridge chord progression. A common addition is to put a minor chord before each dominant chord: Amin7, D7, Dmin7, G7, Gmin7, C7, Cmin7, F7. Beboppers love this variation because of the musically gymnastic aspect.
The last section A of Example 2 (starting at bar 25) shows a generalized chord progression, without the additional beboppish harmonic variations found in the first two sections A. This line will work even if other players use different modifications. .
EVEN MORE CHANGES
Now let’s take a look at some popular ways to navigate “rhythm changes”. Example 4 shows the first four bars of section A, using a bass line similar to that performed by Walter Page in the hit Jumpin ‘at the Woodside by Count Basie in 1938. Example 5 is a bebop variation of first four bars, which uses dominant chords in chromatic movement.
Example 6 shows another common variant of the bebop. Note that the Bdim7 in measure 1 leads to Cmin7 in measure 2. The C & min7 in measure 2 leads to Dmin7 in measure 3.
Example 7 shows one of many ways to navigate section B (bridge) of ârhythm changesâ. Instead of two bars of D7, we find an Amin7 to D7 in bar 1, followed by an E # min7 to A # 7 in bar 2. The E # min7 and A # 7 are at an interval of one. Amin7 and D7 tritone, and lead well to the G7 chord in bar 3.
This type of progression is called triton substitution, a common bebop harmonic device. When the chords move in a circle of fifths, say, D7 to G7, we can substitute the D7 for the chord at the interval of a tritone, giving A # 7 to G7. Triton substitution adds tension and leads to the next chord in the cycle. If we add a minor chord in front of the dominant (Amin7 to D7), then we can also substitute the minor chord and the dominant chord found at a tritone (E # min7 to A # 7).
How do you go about familiarizing yourself with ârhythm changesâ in all of its variations? Listen to some jazz, and in particular the various ‘rhythm change’ recordings mentioned in this article. Once you have the sound of the progression in your ear, your fingers will lead you to the best notes.