Not sure exactly the sound you're looking for, but you might try Am/G which would be an inverted Am7. The notes would be G A C E.
I'm looking for
Am7 - phrygian. Phrygian mode doesn't allow the b9 as extension, but the 11.
The notes are: a - c - e - g - d.
For example: a song in F major using strictly diatonic chords and diatonic harmonies:
the melody could be like: a-g-a-bb-c
the harmony: Am7 (IIIm7 - phrygian)
BIAB generates always (dorian) m7 with the 9, the b-natural !
(That in fact is an unwanted change of the key)
The b-natural in the comping and the b-flat in the melody of course clash and sound terrible.
I tried
C69/A (c-e-g-a-d) and
D9sus4/A (d-g-a-c-e), but BIAB in both cases add the B-natural. (For C69 this is simply wrong, because C6 means 6 instead of maj7 - for D9sus4 it's possible)
Is there a way to enter the voicings/harmonies I want and F4 doesn't overwrite them ?