Basic four note chords
For the most part four note chords are extensions of triads or altered triads, such as sus chords. In their most basic form a note is added on top, up a maj7 or (b)7.
Four note chords can be inverted, but for the moment let’s not worry about that. The most common are:
The maj7 and (b)7 is also added to Xsus, Xsus2, X 4:2 sus, X aug and an altered major chord with b5, this way:
- X7 4:2 sus
- X aug7