Chord Distribution Analysis
| Chord Symbol | Count | Frequency |
|---|---|---|
| Bb7 | 8 | 17.8% |
| Bbm7 | 7 | 15.6% |
| Ebm7 | 6 | 13.3% |
| F7 | 5 | 11.1% |
| Dbmaj7 | 3 | 6.7% |
| Eb7 | 3 | 6.7% |
| Abm7 | 2 | 4.4% |
| Db7 | 2 | 4.4% |
Key Patterns Detected
| Pattern | Function | Frequency |
|---|---|---|
| Bb7 -> Ebm7 | Resolution (Minor) | 6 |
| F7 -> Bbm7 | Resolution (Minor) | 5 |
| Bbm7 -> F7 | Setup (Major Key) | 4 |
| Ebm7 -> Bb7 | Setup (Major Key) | 4 |
| Abm7 -> Db7 | Setup (Major Key) | 2 |
| Fm7 -> Bb7 | Setup (Major Key) | 1 |
| Eb7 -> Bbm7 | Resolution (Minor) | 1 |
| Bbm7 -> Eb7 | Setup (Major Key) | 1 |
| Ab7 -> Dbmaj7 | Resolution (Major) | 1 |
| Cm7b5 -> F7b9 | Setup (Minor Key) | 1 |
Harmonic Highlights
- The progression centers on frequent tonicizations of the relative minor (Bb minor) and the subdominant (Gb), utilizing extended ii-V-i and ii-V-I sequences to delay tonic arrival.
- It features a “back-door” dominant resolution where B7 (bVII7) resolves chromatically to Dbmaj7 (C# major), providing a sophisticated alternative to the standard V-I cadence.
- The harmony employs a secondary dominant chain (Bb7 to Eb7 to Ab7) typical of Rhythm Changes, creating strong forward momentum through the cycle of fourths.
Improvisation Focus Chord tone targeting and horizontal phrasing using the Bb minor and Db (C#) major scales.
Difficulty Rating 4/5. The rapid-fire harmonic rhythm and frequent modulations between minor and major key centers require advanced technical facility and harmonic navigation at typical “Lester Young” tempos.