Watch the Harmonic Minor Scale online guitar lesson by John Stowell from Modern Jazz Improv

Because these two harmonic minor substitutions add a b9 (a 4th above) and #9 (a 5th above), they can be used with the the two melodic minor substitutions (1/2 step above and whole step below) over diminished chords. For example, if my progression were F maj7-F#o-G mi7, F#o could be interpreted as D7 altered (Eb or C mel or harm mi/ G or A harm mi). As with all complex sounds, play your ideas slowly to connect patterns, internalize sounds and develop a melodic vocabulary.