Quartal Harmony

Stack thirds and you get the building blocks of Western harmony — triads, seventh chords, the whole scaffolding of pop, classical, and blues. Stack fourths and something stranger happens. The chord stops declaring itself. It hovers.

That hovering quality is exactly what McCoy Tyner was after when he anchored John Coltrane’s modal explorations in the early 1960s. His left hand would plant these dense, resonant clusters — not a minor seventh chord with its clear emotional signal, but something more like a weather system. The harmony was present, even forceful, but it refused to tell you where it was going. That refusal is the whole point.

What a Quartal Chord Actually Is

A tertian chord — the standard kind — is built by stacking intervals of a third. C, E, G. Add another third: B. That’s a Cmaj7. The logic is familiar almost to the point of invisibility.

A quartal chord does the same thing with fourths. C, F, B♭. Or D, G, C. Three notes, each a fourth apart. You can keep stacking: D, G, C, F. Four notes, same principle. The interval pattern is consistent, which gives quartal chords a kind of structural neutrality — unlike a dominant seventh, which practically screams its function, a quartal chord doesn’t strongly imply resolution in any particular direction.

This is because the fourth is an ambiguous interval. It’s perfect — acoustically pure — but contextually slippery. In classical counterpoint it was treated with suspicion, almost as a dissonance depending on its placement. That instability is a resource, not a flaw.

The Sound in Practice

Wayne Shorter’s compositions are full of moments where the harmony seems to exist outside of gravity — chords that aren’t quite major, aren’t quite minor, that suggest a mood rather than a key. Quartal voicings are part of how that effect is achieved. They’re also all over the work of Herbie Hancock and Bill Evans, who used them to create space within otherwise conventional chord progressions.

But you don’t have to be a jazz pianist to use them. Radiohead’s later records — Kid A, Amnesiac, In Rainbows — contain keyboard and guitar textures built from similar principles, even if they arrived there through instinct and production rather than theory. The opening of How to Disappear Completely has that same unmoored quality: harmony that describes emotional space rather than functional direction.

On guitar, quartal voicings fall surprisingly naturally on the fretboard. The standard EADGBE tuning means that most adjacent strings are already a fourth apart (with one major third between G and B). A simple two-note shape moved up the neck in fourths generates instant quartal material. Add a third string and you have a voicing that sits cleanly under the fingers while sounding like something genuinely outside the ordinary.

Using Them Without Getting Lost

The practical challenge is that quartal chords don’t come with built-in directions. They won’t pull toward resolution the way a dominant seventh does. This means you have to supply the motion through other means — melody, rhythm, register, dynamics.

One effective approach is to treat them as colour rather than function. Keep a clear melodic line on top and let quartal voicings be the texture underneath. The melody implies the harmonic direction; the chords provide ambiance. This is essentially what McCoy Tyner was doing — the saxophone lines were handling narrative duty while his chords created a resonant, open field beneath.

Another approach is to use quartal chords at moments of suspension — places where you want the music to feel paused or unresolved before moving back into clearer harmony. They’re naturally suited to intro sections, bridges, or anywhere you want to introduce uncertainty before relief.

It’s also worth noting that quartal chords respond extremely well to open tunings and modal contexts. If you remove the expectation of key-based function entirely — as modal jazz does — the chords stop sounding “ambiguous” and start sounding inevitable. The ambiguity was always relational: relative to the major/minor system that surrounds most Western music. Step outside that system and quartal harmony stops being strange. It becomes the native language.

You can start simply. Take any note and go up a fourth, then up another fourth. Play those three notes together. Move the whole shape up by a step. Notice how the character changes differently than it would with a triad — more fluidly, with less sense of arriving somewhere definitive. That quality, once you recognise it, becomes a tool. A chord that feels like open water rather than solid ground.

Some music needs to declare itself. Quartal harmony is for the times when you want to leave something open — not unfinished, but genuinely expansive, the way a long pause in a conversation can say more than any sentence.

Explore chord voicings and harmonic ideas with Resonillator’s Chord Tool, free in your browser.