Watch the Shell Voicings online guitar lesson by Frank Potenza from Jazz Harmony Handbook
We begin by observing that "Rhythm Changes" is a 32 bar AABA form, in contrast to the shorter 12 bar blues forms we've been examining. This segment focuses on the basic harmony being played using shell voicings. You'll see that the A sections are pretty much identical, except for the last 2 bars of the second A section, and that the bridge is a backcycling sequence that begins on D7 and cycles back to the key of Bb. "I Got Rhythm" was written in 1930 by George and Ira Gershwin, originally written for the musical comedy “Girl Crazy”.