Talk:Chord substitutions

"Ab D F# C" :: Ab minor7#9

Not sure where you're getting this chord name from. This chord is simply Ab7-5 (at least an enharmonic equivalent), or an inverted D7-5.

Ab minor 7 (leaving off #9 because it's redundant for a minor chord) is Ab Cb Eb Gb.

Removing the note A from a D7 chord leaves D (1), F# (3) C (b7). We call the third (3/b3) and seventh (7/b7) the guide tones of a chord. In a dominant chord these guidetones form a tritone interval. This tritone divides the octave in half. Hence, F# - C =  tritone     but also   C - F# = tritone     (3 becomes b7 and b7 becomes 3) If C= 3rd of X and F#=Gb  then    X= Ab7.

Also, you refer to Ab minor in the bass, and this is only usefull in the context of polychords.