A description of the six natures of the jazz chord which are the major 7th chord, the minor 7th chord, the dominant 7th chord, the half diminished 7th chord, the diminished 7th chord and the suspension chord. Now let's see the chords of four sounds by adding the seventh to the basic triads. For example, the major seventh chord on C, consisting of a major third, a perfect fifth and a major seventh, the minor seventh chord, consisting of a minor third, a perfect fifth and a minor seventh, the dominant seventh chord, consisting of a major third, a perfect fifth and a minor seventh, the half diminished seventh chord, consisting of a minor third, a diminished fifth and a minor seventh, the diminished seventh chord, consisting of a minor third, a diminished fifth and a diminished seventh (where the A or Bbb note is the diminished seventh of C), and finally, the suspension chord, consisting of a perfect fourth, a perfect fifth and a minor seventh. We will do the same exercise than the triads, going up and down over one octave with all seventh chords, by semitones.