Chord Distribution Analysis

Chord SymbolCountFrequency
Fmaj7716.7%
Gm7511.9%
C7511.9%
B0749.5%
D737.1%
F637.1%
Bbm724.8%
Eb724.8%

Key Patterns Detected

PatternFunctionFrequency
Gm7 -> C7Setup (Major Key)5
C7 -> Fmaj7Resolution (Major)3
Bbm7 -> Eb7Setup (Major Key)2
Eb7 -> Abmaj7Resolution (Major)2
Abmaj7 -> Db7Setup (Major Key)2
D7b9 -> Gm7Resolution (Minor)2
D7 -> Gm7Resolution (Minor)1

Harmonic Highlights

  • Features a rapid modulation to the bIII key area (Ab major) via a ii-V sequence (Bbm7-Eb7), a hallmark of sophisticated swing-era compositions.
  • Employs the #iv diminished chord (B°7) as a chromatic connector between the subdominant (Bbmaj7) and the tonic (Fmaj7/C).
  • Utilizes secondary dominants (D7 and D7b9) to create a strong pull toward the ii chord (Gm7), reinforcing the home key.
  • The structure relies on recurring ii-V-I turnarounds in F major to anchor the harmony amidst temporary modulations.

Improvisation Focus

Voice leading through the ii-V-I sequences, specifically targeting the shift from the F major tonic to the temporary Ab major tonal center.

Difficulty Rating

3/5: The progression is largely diatonic to F major but requires fluid navigation of the quick shift to Ab major and back.