Like the Blues, “rhythm changes” is one of the most common song forms in jazz music. This 32-bar AABA form and its accompanying chord progression is derived from George Gershwin’s iconic composition “I Got Rhythm,” hence the name “rhythm changes.”
Jazz history is rich with examples of contrafacts (which are original songs created by composing a new melody over a preexisting set of chord changes) based on the rhythm changes form and progression. Famous rhythm changes tunes include “Anthropology,” “Dexterity,” “Oleo,” “Lester Leaps In,” and “Cottontail” among many, many others.
The rhythm changes form is highly flexible and there are a wide variety of ways to conceptualize this classic chord progression while improvising over it.
In this lesson, I want to look at just a few ways you can break down and approach the “A” section and the “B” section of a rhythm changes.
The “A” Section
Let’s start with the A section. I break it down into two large categories or approaches:
1. You can think about every individual chord separately and try to “catch” all the changes by clearly referencing them as you play.
2. You can try to simplify the harmonic progression and play in key centers.
Trying to catch all the changes is difficult, but you can really generate a lot of cool lines and chromaticism this way, especially when you start exploring all of the various types of common chord substitutions that are available for you to exploit, such as tritone substitutions, diatonic substitutions, and superimpositions.
Here’s a visualization of 3 versions of the “A” section of a rhythm changes in C (labeled A1, A2, and A3) showing various chord substitutions and alternate versions in parentheses and brackets:
Here’s an example of 8 bars over one version of a rhythm changes “A” section in C using continuous 8th notes which outline the voice-leading within the harmony and use a lot of chromaticism:
For simplicity and contrast, try reducing the whole 8 bar phrase into a few key centers (for example, I -> IV -> I or V of I -> I -> V of IV -> IV -> V of I -> I).
Here’s a visualization of 2 versions of the “A” section of a rhythm changes in C showing simplified harmonic analysis:
Here’s an example of 8 bars over one version of a rhythm changes “A” section in C using continuous 8th notes which play around with simplified key centers and use only a bit of chromaticism:
The “B” Section
Now let’s tackle the rhythm changes Bridge, or the “B” section of the AABA form.
Since the bridge of a rhythm changes is, at its simplest, 4 dominant 7th chords, you can do a lot in terms of substitutions, alterations, additions, etc. You can:
1. Treat them as basic dominant chords and use bebop scales.
2. Treat them as II-V’s.
3. Alter any or all of them (it’s especially useful to alter the 2nd and 4th dominant chords of the bridge and play the 1st and 3rd ones as a dominant 7 (#11)’s.
4. Superimpose other chords, including chromatic chord progressions.
5. Use diminished scales.
Here’s a visualization of some of the various ways you can think about the chord changes in the bridge of a rhythm changes in C showing chord substitutions and alternate versions in parentheses and brackets:
Here are 5 examples of rhythm changes bridges exercises using the different approaches described above:
I hope you find these approaches to rhythm changes helpful and fun to practice!