I know how to harmonize a normal scale to 4-note chords (maj7,7,m7 and °), but I lately wondered how I may build the chords on a minor scale(not really, but the song i played this chord was in the blues shape and the minor pentatonic/blues scale fit it well) if the first chord is an A7#9.
I just built the other chords on the minor scale with a D# (#9 in C major) instead of a D in them, but I wondered if I should take a #9 of A minor although the chord was a major one.
Any help would be apperciated. Tobias