Chord Substitutions and Reharmonization in Jazz Arranging: A Practical Guide
One of the defining characteristics of jazz is its harmonic sophistication — the way a familiar melody can be transformed by the chords placed beneath it, the way a standard can sound fresh and surprising even after thousands of performances. At the heart of this harmonic creativity lie two closely related techniques: chord substitution and reharmonization.
For jazz arrangers, these tools are essential. They allow you to add color, tension, and surprise to your arrangements, to create smooth voice leading between chords, and to give a well-known tune a fresh perspective. This guide will walk through the most important substitution and reharmonization techniques, with practical guidance on how to apply them in big band and small ensemble writing.
Understanding Harmonic Function
Before diving into specific techniques, it is essential to understand the concept of harmonic function. In tonal music, chords serve one of three primary functions:
Tonic function (I, Imaj7, vi): Chords that create a sense of rest and resolution. Subdominant function (IV, IVmaj7, ii, ii7): Chords that create a sense of motion away from the tonic. Dominant function (V, V7, vii°): Chords that create tension and a strong pull toward resolution.
Chord substitution works by replacing a chord with another chord that serves the same harmonic function. The substitution may share common tones with the original chord, or it may create a chromatic voice-leading connection that makes the harmonic motion feel smooth and inevitable.
The Tritone Substitution