ach dominant 7th in mm. 2–4 is subsequently expandedwith the ii≤57–V or ii7–V7 progressions, thereby doubling the rate of harmonic rhythm. Inm. 2, then, A7 becomes Emin7 (≤5)–A7; in m. 3, G7 turns into Dmin7–G7; and, in m. 4,F7 expands into Cmin7–F7.Comparing the second half of each A section shows that the first A is harmonically openand ends on a ii 7–V7 in m. 8, while the second and the last A feature closed harmoniccadences on I in m. 16 and m. 32, respectively. The bridge in mm. 17–24 has a symmetricalphrase structure and slower harmonic rhythm, which redirects the harmony from I to IVin m. 19 and, then, to ≤VI in m. 23. These key areas are tonicized with local ii7–V7progressions. The choice of these tonal areas corroborates an interesting fact about theoverall tonality of bebop tunes with respect to jazz traditions. The subdominant key areahas always had strong blues underpinnings and the flat submediant was one of the fewchromatic regions that ragtime or early jazz tunes allowed in their harmonic structure.3