The scale tone chords studied so far involve the placement of two notes (separated by an interval of a third) above a root note. This method of building scale tone chords can be extended by adding another note (also an interval of a third). In each case the note added is a seventh above the root note of the scale tone chord, as introduced in Lesson 12. When this seventh note is added to a scale tone chord, the chord becomes one of the following chord types: major seventh (maj7), minor seventh (m7), dominant seventh (7) or half diminished seventh (N7).
The I and IV major scale tone chords become major seventh (maj7) chords.
The II, III, and VI minor scale tone chords become minor seventh (m7) chords.
The V major scale tone chord becomes a dominant seventh (7) chord.
The VII scale tone chord becomes a half diminished seventh (N7) chord (sometimes called a minor seventh flattened fifth (m7b5).
These new scale tone chords are represented here.
From this example, the scale tone chords for any key will be: