I will like to talk about the 9 (add 6) chord. This chord is a nice one to use in worship songs.
You can use this for the 2 chord or the 1 chord.
E.g When playing a 6-2 progression, you can play a minor 9 for the 6 chord and a 9 (add 6) for the 2 chord. Similarly, when playing a 5-1 progression that does not end a song, you can play a 5 minor 9 chord, then a 1 9 (add 6) chord.
Here’s an example of such a chord.
D♭ 9 (add 6)
To play it, you play D♭ on the left hand. Then play F B♭ B and E♭ on the right hand.
An easy way to think about it is to play the root note of the chord on the left hand, then play a quartal 3 chord with an added ♭5 on the right hand.
For example, F is the 3 chord on the D♭ major scale. F B♭ and E♭ is the F quartal chord. And B is ♭5 on the F scale.
Using this trick, it is easy to play 9 (add 6) for any key. That’s all for now. Enjoy.