Chord Distribution Analysis

Chord SymbolCountFrequency
Ab7313.0%
Db07313.0%
Db6313.0%
Fm7b528.7%
Bb7b928.7%
Ebm728.7%
Fmaj728.7%
Dbmaj714.3%

Key Patterns Detected

PatternFunctionFrequency
Fm7b5 -> Bb7b9Setup (Minor Key)2
Bb7b9 -> Ebm7Resolution (Minor)2
Ebm7 -> Ab7Setup (Major Key)2
Gm7b5 -> C7b13Setup (Minor Key)1
C7b13 -> Fmaj7Resolution (Major)1
Abm7b5 -> Db7b13Setup (Minor Key)1
Db7b13 -> GbmResolution (Minor)1

Harmonic Highlights

  • The progression opens with a ii-V of ii (Fm7b5–Bb7b9 leading to Ebm7), immediately establishing a sophisticated secondary dominant relationship that sidesteps the tonic.
  • A brief but significant modulation to F major (the mediant) occurs via a Gm7b5–C7 sequence, showcasing Strayhorn’s signature use of chromatic “side-slipping” and distant tonal centers.
  • The integration of the minor subdominant (Gbm) and diminished passing chords (Db°7) provides a dense, Ellingtonian texture that favors smooth voice leading over standard functional cycles.

Improvisation Focus Chord-tone targeting and the Altered Scale to navigate the frequent secondary dominants and chromatic transitions.

Difficulty Rating 4/5; the rapid harmonic rhythm and frequent modulations to non-diatonic keys require advanced theoretical knowledge and precise melodic mapping.