Quartal Chords
5 chords in this group
Quartal and quintal chords are stacked in fourths or in fifths instead of thirds. They are not triads with notes missing — they are built by a different rule, and the result is harmony that does not announce a key or lean towards a resolution.
Stacking fourths
Three notes a fourth apart from C give C, F and B♭; four give C, F, B♭ and E♭. Because every interval is the same, no note claims to be the root, and the ear has nothing to anchor to.
That is the point rather than a defect. The same shape can sit on any degree of a scale, and moving it produces a run of chords that sound consistent without forming a cadence.
Stacking fifths
Two fifths from C give C, G and D; three give C, G, D and A. Where fourths float, fifths are the most stable sound in music — and the four-note version, collapsed into an octave, is simply a major pentatonic without its third.
This is the open, wide sound of orchestral writing about landscape, and it is also what a drone instrument has always produced. Stability with no mode named.
The So What chord
One voicing in this group has a name of its own: three fourths with a major third on top — C, F, B♭, E♭, G. Bill Evans played it in the introduction to Miles Davis's So What in 1959, and it entered common use from a single record rather than from theory.
Its notes are those of Cm11. Stacked in thirds that is an everyday chord; stacked in fourths it is recognisable in a second. Voicing here is not presentation, it is the substance.
Why guitarists have an advantage
Standard tuning is mostly fourths, so a straight barre across four strings already gives a quartal stack. C, F and B♭ is x333xx — one finger. The So What voicing is 88888x, a barre at the eighth fret.
The exception is the second and third strings, where the tuning gives a major third. Any quartal shape crossing that pair needs one extra fret, and that single irregularity is the only thing to remember.
Where this harmony is used
It arrived with early twentieth-century composers looking for chords that sounded modern without dragging tonal obligations behind them, and it reached jazz in the 1950s along with modal playing. When the harmony stops moving, how each chord is built becomes the main event.
Today it is standard vocabulary in film scoring and in modern piano writing. A quartal stack over a static bass fills space without ever suggesting where the music should go next.
Frequently asked questions
What is quartal harmony?
Chords built by stacking perfect fourths rather than thirds, giving a sound with no clear root.
How do I play a quartal chord on guitar?
A barre across the lower strings: x333xx gives C, F and B♭. Standard tuning is already in fourths.
What is the So What chord?
Three stacked fourths with a major third on top — C, F, B♭, E♭, G — named after the Miles Davis piece it opens.