The triad and the seventh intervals forming the chord may be identified. In order to use this method, the structure of each of the different types of seventh chords should be shown. Seventh chords are four-note chords of which the pitch classes can be arranged as thirds is called a seventh chord.
A four-note chord whose pitch classes can be arranged as thirds is called a seventh chord.
Like with a triad, the pitch classes belonging to a seventh chord occupy adjacent positions (a four-pitch-class clump) on the circle of thirds. The four members of a seventh chord are the root, third, fifth, and seventh. There are five qualities of seventh chords that appear in diatonic music: major seventh, dominant seventh, minor seventh, diminished seventh (also called fully-diminished), and half-diminished seventh.
