Quartal Harmony
Quartal harmony, which involves stacking intervals of fourths rather than thirds, is widely used in jazz and other modern musical styles due to its ambiguous and open sound. Here are the most common contexts in which quartal harmony is employed:
1. Modal Jazz
Modal jazz often emphasizes scales and modes rather than functional chord progressions. Quartal voicings work well here because they avoid the strong tonal pull of tertian harmony (chords built on thirds). They provide a more open, ambiguous sound that fits the modal approach.
Example: McCoy Tyner’s playing with John Coltrane, where quartal voicings emphasize the mode rather than implying a specific chord function.
2. So What Voicing
This voicing, made famous by Miles Davis in “So What,” uses a stack of fourths over the tonic and subdominant, creating a quartal chord. It’s often used for minor 7th chords and can be shifted diatonically across a scale.
Example: In D Dorian, the voicing is D-G-C-F-A, stacked in perfect fourths.
3. Post-Bop and Modern Jazz
In post-bop and modern jazz styles, quartal harmony is a staple of both comping and soloing. It creates tension and harmonic ambiguity, which fits the more complex harmonic explorations in these styles.
Guitarists and pianists use quartal voicings in non-functional harmony, where chords are less about resolution and more about creating texture.
4. Improv over Modal and Pedal Point Sections
Quartal harmony is excellent for improvising over pedal points or static modal sections, where harmonic movement is minimal. The openness of quartal chords allows players to float over the pedal tone without implying a strong harmonic resolution.
Example: In a modal jam on C Dorian, quartal chords like G-C-F or A-D-G can sit over the C pedal point, leaving the tonality ambiguous.
5. Chordal Extensions and Altered Dominants
Quartal harmony can be used to imply chord extensions (9ths, 11ths, 13ths) without explicitly spelling out the thirds of a chord. This is especially useful when voicing altered dominant chords or creating polychords.
Example: A quartal voicing built on a G dominant might be D-G-C-F (G7sus4 sound).
6. Suspended Chords
Quartal voicings often appear in suspended chords (e.g., sus4, sus2). The stacked fourths naturally create a suspended quality by avoiding the third of the chord, leaving the tonality unresolved.
Example: Gsus4 can be voiced as G-C-F, creating a quartal sound.
7. Fusion and Progressive Rock
Jazz fusion and progressive rock often incorporate quartal harmony for its modern, less predictable sound. It adds texture and avoids the traditional major/minor harmonic structures found in more conventional rock or pop music.
Example: Guitarists in fusion bands like John McLaughlin or Allan Holdsworth use quartal voicings in their comping and improvisation.
8. Non-Functional or Open-Ended Progressions
Quartal harmony is commonly used in progressions that don’t follow traditional tonal harmony (i.e., V-I cadences). It works well in pieces that avoid strong resolutions and instead favor non-functional progressions, adding to the harmonic ambiguity.
Example: A progression might move from quartal voicings with no clear root movement or tonic resolution, creating an ethereal or floating harmonic texture.
9. Film Scoring and Modern Classical Music
Quartal harmony is often employed in film scores and modern classical compositions to create a sense of mystery, tension, or space. The unresolved nature of fourths contributes to the atmospheric and textural aspects of the music.
Example: In a soundtrack, quartal voicings can be used to evoke a futuristic or uncertain mood.
Quartal harmony is valued for its flexibility and ability to enhance modal playing, create ambiguous tonalities, and provide unique textures in modern jazz, classical, and fusion contexts.
