Understanding Jazz Reharmonization Through Classic Examples

How do secondary dominants function as a foundational tool for harmonic substitution?

Secondary dominants function as a foundational tool by creating temporary harmonic gravity that pulls the listener toward a target chord, effectively turning any diatonic chord into a temporary tonic.

• V7/V: This chord creates a strong pull toward the dominant of the home key, often used in the second bar of a standard blues progression to heighten anticipation.
• V7/ii: Placing this before the ii chord builds tension that resolves into the supertonic, common in the opening phrases of jazz standards.
• V7/vi: This substitution targets the relative minor, adding a melancholic, sophisticated turn to otherwise simple major-key sequences.
• V7/IV: Using this creates a bluesy, gospel-inflected movement toward the subdominant.

What is the role of tritone substitution in creating smoother voice leading between chords?

Tritone substitution relies on the shared guide tones of two dominant chords whose roots are separated by a tritone, such as G7 and Db7. Because both chords contain the same F and B natural, the substitution allows the bass to descend chromatically, creating a seamless connection that feels more elegant than the standard circle-of-fifths movement. For example, in a ii-V-I progression in C major, replacing G7 with Db7 creates a smooth bass line moving from D to Db to C.

This technique is most effective when the melody note is a chord tone of the new dominant, like the flat-fifth or minor-seventh. An exception exists when the melody note is the natural root of the original dominant chord. In that case, using a tritone substitution creates a harsh minor-ninth interval against the melody, which can sound jarring unless the arranger specifically intends to create that dissonant, modern texture.

In what ways does the use of the ii-V-I progression serve as a template for reharmonizing static melodies?

The ii-V-I progression acts as a universal harmonic container that replaces static or slow-moving chords with a predictable, high-energy sequence of tension and resolution.

1. Identify targets: Scan the lead sheet for chords that last two or more bars.
2. Calculate ii-V: Insert the ii chord two beats before the target, and the V chord on the final two beats.
3. Check melody: Make sure the melody notes align with the chord tones of the new ii-V-I.
4. Voice leading: Use root movement by fifths to keep the progression sounding grounded.
5. Adjust extensions: Add 9ths or 13ths to the V chord to increase the harmonic interest.

How does modal interchange allow musicians to introduce borrowed chords from parallel keys?

Modal interchange involves borrowing chords from the parallel minor key to add emotional depth and unexpected color to a major-key progression. By pulling chords like the iv minor or bVI major from the natural minor scale, a musician can create a sense of longing or surprise without leaving the established tonal center. Many people assume that modal interchange requires changing the entire key signature, but it actually functions best as a fleeting, temporary shift that resolves quickly back to the home key, maintaining the listener's sense of stability.

What are the primary differences between functional and non-functional reharmonization techniques?

Functional reharmonization relies on traditional voice-leading principles to maintain tonal direction, while non-functional techniques prioritize color and parallel movement over standard cadences.

• ii-V-I: This functional sequence establishes a clear destination, providing a sense of arrival that satisfies the ear's expectation for resolution.
• Side-slipping: This non-functional technique involves shifting a chord up or down by a half-step and back, creating a temporary, dissonant suspension of the key.
• Constant structures: These non-functional chords move in parallel, ignoring traditional voice-leading rules to create a modern, lush soundscape.
• Coltrane changes: This functional approach uses rapid, symmetrical root movement to navigate through key centers, intensifying the harmonic rhythm.

How can chord extensions and alterations be utilized to add harmonic density to a basic lead sheet?

Yes, adding extensions like the 9th, 11th, or 13th transforms simple triads into sophisticated jazz sonorities. For instance, changing a basic C major chord to a Cmaj13 adds six distinct pitch classes, significantly thickening the harmonic texture without altering the underlying function of the chord.

What impact does chromatic approach chords have on the forward momentum of a jazz arrangement?

Chromatic approach chords inject energy into an arrangement by creating a sense of urgency that forces the harmony toward its next destination. By placing a dominant-quality chord one half-step above or below the target, the arranger creates a brief, intense moment of dissonance that demands resolution. For example, preceding a Dm7 chord with an Eb7 chord creates a strong, sliding pull that sounds more active than a standard diatonic approach. This technique is particularly effective in uptempo swing tunes where the momentum needs to be maintained across long phrases.

One nuance to consider is the rhythmic placement of these chords. If the approach chord is held for too long, it can confuse the listener about the actual tonal center of the piece. To keep the forward momentum intact, these chords should usually occupy only a short duration, such as a single beat or an upbeat, ensuring they function as a bridge rather than a destination.

How do pedal points provide a structural anchor when applying complex harmonic substitutions?

Pedal points anchor complex substitutions by holding a single bass note, usually the tonic or dominant, while the chords above it change. This technique keeps the harmony grounded, allowing for up to 4 or 8 bars of dense, shifting chords without losing the sense of the original key center.