A jazz term; the chords to George Gershwin's "I Got Rhythm". The verses are not far removed from the blues changes, and are thus quite elemental; the bridge features chord movement in a cycle of descending fifths - also elemental. In the bebop era, many musicians would take the chords of pop songs that were amenable to improvising in the new style, and slap on a suitably oblique bebop melody in place of its singable, Squaresville original; this way they didn't have to pay royalties.