13.7The three most useful 9th chords
Learn these first:
Cmaj9
C E G B D
C9
C E G B♭ D
Cm9
C E♭ G B♭ D
Notice:
the 9th is D in all three.
What changes is the 3rd and 7th.
Again, the 3rd and 7th define most of the chord quality.
13.7 The three most useful 9th chords