By adding more 3rd intervals on top of the various 7th chords, it is possible to create many more chords, notably the various types of 9th, 11th and 13th chords. These will all be dealt with in this lesson, but first there are two more common four note chords worth learning. These are the major 6th chord (usually just called a 6th chord) and the minor 6th chord. These chords are shown below based on the note C.
As with previous chord types, it is important to practice the arpeggios for these sixth chord in all inversions and over the entire range of your instrument. Here is an example demonstrating the use of both major and minor sixth chords.
Another chord type you will encounter is the suspended chord. In a suspended triad, the 3rd of the chord is replaced by the 4th degree of the scale, so its degrees are 1, 4 and 5. It is also common to add a minor 3rd on top of the triad to create a suspended 7th chord. It’s degrees are 1, 4, 5 and 7. Since they do not contain a 3rd degree, suspended chords work equally well in both major and minor keys.
The following example demonstrates the use of the suspended 7th chord. Notice how these chords resolve to a dominant 7th by lowering the 4th degree back to the 3rd.