The b9 and #9 tones were derived from the dominant 7th chords.This is just one approach to a better understanding of the function of the vii7 chord in the harmonic minor mode.Although each vii7 chord has an enharmonic equivalent, and the chord lends itself to inversions every three additional frets, when viewed in proper perspective, there are really 12 vii7 chords. Three sets of four identical sounding chords. The vii7 chord is useful in use of modulations to different keys.
The difference in which passing tones one uses with the full diminished chord are not as apparent when playing fast. However, when playing slower, the difference becomes more noticable and finesse if you are able to stay in the key.
