Chord Distribution Analysis

Chord SymbolCountFrequency
Bbmaj7926.5%
C7617.6%
F7514.7%
Cm7411.8%
Gm738.8%
G725.9%
Em7b512.9%
A7b912.9%

Key Patterns Detected

PatternFunctionFrequency
F7 -> Bbmaj7Resolution (Major)5
Cm7 -> F7Setup (Major Key)4
G7 -> Cm7Resolution (Minor)2
Gm7 -> C7Setup (Major Key)2
Em7b5 -> A7b9Setup (Minor Key)1
A7b9 -> Dm7Resolution (Minor)1

Harmonic Highlights

  • Employs a recurring I-VI-ii-V progression (Bbmaj7-G7-Cm7-F7), utilizing G7 as a secondary dominant (V/ii) to enhance harmonic pull toward the supertonic.
  • Incorporates a II7 chord (C7) acting as a secondary dominant of the dominant (V/V), typical of the “swing era” harmonic vocabulary.
  • Features a brief tonicization of the mediant (Dm) via a minor ii-V (Em7b5-A7b9), introducing a momentary shift in tonal color.
  • Uses chromaticism through the Db7 chord, functioning as a tritone substitute (subV/ii) to create a smooth, descending bass line toward Cm7.

Improvisation Focus Guide-tone voice leading to highlight the resolution of secondary dominants.

Difficulty Rating 2/5; the progression relies on standard jazz turnarounds and stays primarily within the Bb major tonal center, making it accessible for intermediate improvisers.