Seventh Chord Types
By adding more notes on top of the basic triads, it is possible to create many other types of chords. After triads, the next most common chords are seventh chords. Various types of seventh chords are created by adding another note either a major or minor third above the basic triad.
The formulas for the various types of seventh chords are shown below and on the following page. Like triads, once you have memorised each one, practice it in all inversions and transpose it to other keys.
Major Seventh Chord Formula
Dominant Seventh Chord Formula
Minor Seventh Chord Formula
Minor Seven Flat Five Chord Formula
The final type of seventh chord is the diminished seventh. This chord is unusual in that it contains a double flattened 7th degree (~7). This note is actually the same as the 6th degree (A) but it is technically called B~7 because the interval has to be some kind of seventh rather than a sixth because the chord is a type of seventh chord.
Diminished Seventh Chord Formula
The most commonly used types of 7th chord are the Dominant 7th, the Major 7th and the Minor 7th. You learned about dominant 7ths in lesson 6, so you should know the sound of them quite well by now. Here is an example which demonstrates the use of Major 7ths and Minor 7ths along with a dominant 7th.
