A seventh chord is a group of four notes which are related by thirds. Seventh chords are similar to triads but with a fourth note a third above the fifth. Notice that the added note is a seventh above the root. Each of the note groupings in the example below is a seventh chord. Notice that each one is a stack of three thirds. Sevenths add an additional dimension of sound to a triad. Compare the sound qualities of the seventh chords with their respective triads.
Seventh ChordsEach of the notes of a seventh chord is given a name. The bottom note (when stacked by thirds) is the root. The second note is called the third, the third note the fifth, and the top note the seventh.
There are five qualities of seventh chords which are commonly used: major-major, major-minor, minor-minor, diminished-minor, and diminished-diminished. The seventh chord quality is determined by the quality of the bottom triad and the seventh which the chord contains. Click on the buttons in the example below to see the spelling for each of the five seventh chord qualities built on the note 'G'. Pay close attention to the quality of the bottom triad and the quality of the interval from the root to the seventh.
Seventh Chord QualitiesMajor-Major ♦ Major-Minor ♦ Minor-Minor
Dim-Minor ♦ Dim-Dim
The following examples show a few ways in which seventh chords are used in musical compositions.
In the following example alternating major-major seventh chords (GM7 and DM7) are used to accompany a melody.
Gymnopedie No. 1 by Eric Satie
This example by J. S. Bach begins and ends on an arpeggiated C major triad. The second measure has a D minor-minor seventh chord with the seventh in the bass and the third measure contains a G major-minor seventh chord with the third in the bass.
from Prelude No. 1 by J. S. Bach
The Mozart example below begins on a C minor triad in the first measure. The second measures moves to an F minor-minor seventh chord. The third measure contains a Bb major-minor seventh chord. The fourth measure contains an Eb major-major seventh chord. And the final measure contains two chords-An Ab major-major seventh chord without a fifth (Eb) and a D diminished-minor seventh chord without a fifth (Ab).
from Sonata, K. 332 by Mozart