reharmonize

Reharmonize refers to changing the chords that accompany a melody without altering the melody itself. This harmonic reinterpretation can change mood, color, tension, and motion, and is used in performance, arrangement, or composition. Reharmonization is especially common in jazz standards but appears in classical, pop, and film music when composers or performers seek a fresh harmonic perspective on a familiar melody.

Techniques include diatonic substitutions, where a chord is replaced by another from the same key family; secondary dominants, which insert dominant chords that resolve to a following chord; modal interchange, borrowing chords from parallel keys (for example, using a minor iv in a major key); chromatic approaches and diminished chords; and tritone substitutions, where a dominant chord is replaced by a chord a tritone away. Other tools include planing (parallel chord movement), altered tunings/extensions, and pedal tones to anchor the melody while the harmony shifts. Careful voice leading preserves the integrity of the melody while providing new harmonic color.

In practice, reharmonization is a core technique of jazz improvisation and arrangement, enabling players to interpret standards with inventive chord choices. It also appears in contemporary pop and fusion, and in classical adaptations where composers revisit existing tunes with richer or more distant harmonies. The aim is not to change the melody but to offer new harmonic narratives, emotional shades, or structural possibilities for the same melodic line.