Where did you find these chords at?
1) Bb maj7:
R.H: D G C (Bbmaj7 notes are Bb D F A without G & C, how come these two notes are played in this case?)
L.H: Bb
The is chord should be called a Bb13 not a BbM7. If you stack the notes in thirds, you should have: Bb-D-F-A-C-E-G It's missing the C and the E, but it's still considered a Bb13 chord.
2) Eb7(b9)
R.H: G C E (How come C is included in the chord ? )
L.H: Eb Db
This chord should be called an Eb13, not an Eb7 (b9). If you stack the notes in thirds, you should have: Eb-G-Bb-Db-F-Ab-C It's missing the Bb, F, and Ab, but it is still considered an Eb13 chord.
3) Ab6/9
R.H: Bb Eb (Bb should be A ? coz b9 = Bbb = A?)
L.H: Ab C F
This chord is correct. It is an Ab major chord with an added 6th and added 9th. If you stack the notes in thirds, you should have: Ab-C-Eb-F-Bb
Does that answer all your questions? Any other theory experts can back me up to make sure all this is correct.
