St. Louis Blues (C major) - Jazz Analysis & Chords

Chord Distribution Analysis

No obvious ii-V patterns detected.

Harmonic Highlights

• Employs a traditional 12-bar blues framework using I7, IV7, and V7 chords (G7, C7, and D7), where the dominant 7th quality defines the tonic stability.
• Features a distinctive 16-bar minor bridge section—historically referred to as the “Tango” section—which typically modulates to the parallel or subdominant minor (Gm or Cm).
• Utilizes a V7-IV7-I7 turnaround (D7-C7-G7) in the final bars of the blues sequence, a characteristic move of early urban blues that predates the standard jazz ii-V-I.
• Integrates multi-thematic formal structures, alternating between 12-bar blues and 16-bar song forms to bridge ragtime and early jazz styles.

Improvisation Focus G Blues Scale (G, Bb, C, Db, D, F).

Difficulty Rating 2/5: The 12-bar sections are fundamental for beginners, though the transition into the minor bridge and the syncopated rhythmic shifts require moderate structural awareness.