Quartal (3 notes)
q3
0 - 5 - 10Stacked perfect 4ths
About Quartal (3 notes)
A three-note quartal chord is built from two stacked perfect fourths — in C that is C, F and B♭. It is not a triad with something missing but a chord assembled on a different principle: where tertian harmony stacks thirds and produces a root, quartal harmony stacks fourths and produces no clear root at all.
Notes and formula
The formula is 0 – 5 – 10 in semitones: C to F is five, F to B♭ is another five. There is no third in the chord, so it has no quality, and no fifth above the root, so it has no anchor.
Because the intervals are equal, any of the three notes can be heard as the bottom of the stack. Which one sounds like the root is decided entirely by the bass and by what came before.
Why fourths sound the way they do
A perfect fifth reinforces the overtone series of its lower note, which is why triads fuse into a single sound. A perfect fourth does not, so a stack of them stays audibly separate — three voices rather than one chord.
That separateness is the point. Quartal voicings sound open and unresolved not because they are dissonant but because nothing in them establishes a hierarchy.
How to play it
On guitar it is x–3–3–3–x–x: one finger across three strings, which the tuning in fourths makes trivial. This is why quartal harmony entered guitar playing early and stayed.
On piano the shape is a stretch of a ninth in one hand, and pianists usually split it between hands or drop the top note.
Where it belongs
In modal jazz, where a static harmony needs voicings that do not insist on a key. In film scoring, for the same reason.
It also appears as a way of comping over a minor eleventh chord: the same notes, read as a rootless fragment of a larger tertian chord rather than as a chord in its own right.
Searching for it
Quartal three-note chords have essentially no search demand as a named object — people meet quartal harmony through recordings and through the voicings of specific players rather than by looking it up.
This page exists for completeness of the catalogue and for the reader who has already heard the sound and wants to know what it is called.
Frequently asked questions
What notes are in a three-note quartal chord on C?
C, F and B♭ — two perfect fourths stacked. On guitar, x–3–3–3–x–x.
Is it major or minor?
Neither. It has no third, and unlike a power chord it has no fifth either, so nothing in it suggests a quality or a key.
How is it different from a sus4 chord?
Csus4 is C–F–G: a root, a fourth and a perfect fifth, which anchors it. The quartal chord replaces the fifth with another fourth and loses the anchor.