Oleo

Composed by Sonny Rollins, "Oleo" is based on the chord changes to Gershwin's "I Got Rhythm". Other than the blues, "rhythm changes" is the most important set of chord changes a jazz musician should be able to blow over. The A section is based on a I-VI-ii-V progression (with some variations) and a cycle of fourths progression on the bridge (starting on the III7).