From the Archive: Performing ‘I Got Rhythm’ | Feature


“Let’s play rhythm!” It’s a phrase that jazz musicians often hear during jam sessions or at the bandstand. It means, ‘Let’s improvise on the harmonic structure of the great classic American song, I Got Rhythm.’ Jazz musicians used the shape and harmony of “rhythm changes” (the jazz term for the harmonic structure of I have rhythm) for years as the basis for new melodies and jazz improvisations. The most enduring and widely played forms of jazz are the twelve-bar blues and “rhythm changes”.

In this article, we’ll use walking basslines to explore some of the many harmonic variations of “beat changes.”


I have rhythm was written by George and Ira Gershwin in 1930 and found its way into the series Crazy girl. After Ethel Merman’s performances in the original Broadway production, jazz musicians of the day quickly picked 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 rhythmwith Gene Krupa, Teddy Wilson and Lionel Hampton, released on Sony as Jazz concert at Carnegie Hall.

The song’s most famous recording as a bass comes from a concert at New York City Hall in 1945. Leroy ‘Slam’ Stewart and tenor saxophonist Don Byas play an incredible duet to the tune. Slam weaves its way into a driving two-beat bass line under Byas’s solo, then delivers its own incredible solo, with its signature vocals, in unison, an octave above the bowed bass.

The most enduring and widely played forms of jazz are the twelve-bar blues and “rhythm changes”

The performance is hard to find on CD, but is currently available at most digital music stores. During the swing and bebop era, many jazzers used the harmonic structure of Gershwin’s classic as the basis for new melodies. When jazz musicians talk about “rhythm changes,” they’re referring to the harmony, or chord progression and shape of the original song. A jazz melody based on the harmony of a different song in this way is called a contrafact.

Songs like Duke Ellington’s cotton tailLester Young’s Lester leaps 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 contrafacts of “changes of rhythm” composed by alto saxophonist Charlie Parker during the bebop era. Other notable contrafacts of “changes of pace” include Sonny Rollins OleoThelonious Monk’s Rhythm-A-Ningand cartoon theme Meet the Flintstones by Hoyt Curtin.

Playing over the harmony to the “rhythm changes” has become one of the ultimate tests of jazz mastery. It provided a common canvas for the past 80 years of jazz history, with everyone from Duke Ellington to Pat Metheny painting a piece of the picture.


What makes “rhythm changes” such a solid basis for improvisation? What makes it so fun to play? The chord progression is simple enough that a musician can successfully improvise on the structure using the pentatonic scale Bb, C, D, F, G. The more adventurous improviser can add substitutions and reversals, techniques we’ll explore here, to create harmony. ever more complicated.

The original form is AABA, four eight-bar phrases. A two-bar tag is added in the original composition, with a repetition of the line “Who could ask for anything more”, which makes the original shape 34 bars long. Almost all jazz contrafacts omit the tag, making “rhythm changes” a basic 32-bar form. In its simplest variant, the first eight bars of “rhythm changes” can be played as in Example 1.

Example 1 092_Strad201104

Jazz players usually choose to add chords to embellish the basic harmony. There are countless variations of ‘tempo changes’, with many subtle differences. Example 2 shows the whole form with some typical variations. In bars 1 and 2, the simple option of example 1 is extended to a reversal.

As the word suggests, a turnaround takes a chord progression around a cycle and back to a starting point. The basic progression from I to V7 in example 1 (B#maj6 to F7) is extended to I, VI7, II7, V7 (B#maj6, G7, Cmin7, F7). In bar 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 turnaround options in the first four bars of “rhythm changes”, and jazz players often spontaneously change the chord progression when improvising.


How do you know when to use “change of beat” variations? This spontaneous reharmonization, on the spot, 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 performer knows several harmonic variations of “rhythm changes”, then it is sometimes second nature to instinctively change or embellish the chord progression in the heat of improvisation. An important aspect that helps jazz musicians choose variations spontaneously is a common repertoire of historically significant jazz songs.

For example, 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 confirmed jazzmen will have already heard both pieces quite a bit (they are classics), it is easy to follow a soloist when he passes from one variation to another during an improvisation. It sounds good when all the musicians in the bandstand are always playing the same harmonic variations, but it’s not always imperative.

Sometimes a soloist (or pianist or bassist) will add a variation that the other players don’t hear or choose to pick up. What happens when a player improvises on a different set of chords than the other players? If the players improvise together and describe different variations of the same underlying structure, the sound will always be coherent. For example, if, as in example 3, the pianist plays B#maj6, Gmin7, Cmin7, F7 in the first two bars, while the bass player plays B#maj6, F7, the result is always harmonious.

Example 2 093_Strad201104

They will most likely both 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 convincing. Another appealing aspect of the “rhythm changes” is the bluesy feel that occurs in bars 5 and 6. The movement from the I7 chord (B#7) in bar 5, to the IV chord (E# maj6 or E#7) in bar 6, has a similar feeling to a blues progression. However, bar 6 presents a tricky option: the chord on beats 3 and 4 can be either Edim7 or E#min6. This is an important place for the bass player!

Note that in example 2, bar 6, Edim7 is used, and in bar 14, the alternative choice presents itself: E#min6. Most jazz melodies favor one chord progression or the other, and most jazz players stick to a variation of that bar throughout an improvisation.

The original Gershwin I have rhythm The melody is best harmonized using E#6 to E#min6 in bar 6. The B section (the third eight-bar phrase, also called the bridge) of the “rhythm changes” begins on the III7 (D7) chord. and moves through the cycle of fifths (D7, G7, C7, F7) finally resolving to B#maj6 to introduce the final A section. There are many popular variations of the chord progression in the bridge. 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 A section of example 2 (beginning at bar 25) shows a generalized chord progression, without the extra harmonic and beboppish variations found in the first two A sections. This line will work even if the other players use different modifications.


Now let’s look at some popular ways to navigate “tempo changes.” Example 4 shows the first four bars of section A, using a bass line similar to that performed by Walter Page in Count Basie’s 1938 hit Jumpin’ at the Woodside. Example 5 is a bebop variation of the first four bars, which uses dominant chords in chromatic motion.

Example 6 shows another common variant of bebop. Note that Bdim7 in bar 1 leads to Cmin7 in bar 2. C&min7 in bar 2 leads to Dmin7 in bar 3.

Example 3 096_Strad201104

Example 7 shows one of the many ways to navigate the B (bridge) section of the “Rhythm Changes”. Instead of two bars of D7, there is 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 tritone of Amin7 and D7, and lead well to the G7 chord in measure 3.

This type of progression is called a tritone 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. The tritone substitution adds tension and leads to the next chord in the cycle. If we add a minor chord before the dominant (Amin7 to D7), then we can also substitute the minor chord and the dominant chord found a tritone away (E#min7 to A#7).

How do you familiarize yourself with “rhythm changes” in all their variations? Listen to jazz, and especially the various recordings of “rhythm changes” mentioned in this article. Once you have the sound of the progression in your ear, your fingers will guide you to the best notes.


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