A good way to think about the melodic minor scale is to consider the scale as an alternative to the major scale, in fact I usually think of a major scale with the minor 3rd. The Melodic Minor harmony with the Major and Diminished harmonies are three different worlds where you can move temporarily at any given time.
Melodic Minor – Cmin/maj7 Chord
It’s used and function as chord I in a II-V-I minor progression as in Dm7b5 – Galt – Cm7. Its often played as substitute for minor 7th chords as long as it’s not part of a II -V in a major progression. It’s also used on IVmin in a major key as in DmG7 – (Fm) – Cmaj
Dorian b2 – DSusb9 Chord
It’s rarely played over a minor chord, but when improvising over Susb9 chords you can use the second mode of the melodic minor scale. For example: D7 – (Dsusb9) – Gmaj. The most important notes are the root, b9, 4th and 6th.
Lydian augmented – Ebmaj#5 chord
It’s a modern way of playing over maj7th chords, you can turn them in major7#5 by using the melodic minor over it, for example: Ebmaj + C melodic Minor = Ebmaj#5
Lydian Dominant – F7#11 chord
It can be used over dominant chords, the Lydian dominant makes a nice change to the Mixolydian Mode.
Mixolydian b6 – G7b13 chord
It’s rarely played over a dominant chord, most musicians use the altered scale over a G7b13 chord, but you can use the C Melodic Minor. We can also use it as sub for major chords as in G7b13 for Gmaj7.
Locrian #2 – A half diminished chord
It function as chord II on a minor II-V-I progression and used on half-diminished chords.
Super Locrian – Altered Dominant chord – B#9#5 (Balt)
Used over a V chord resolving on a I minor, it has all the alterations.
Playing the Melodic Minor over Major Chords
- from the 6th ( A Melodic Minor over Cmaj7) = Cmaj7#5
- from the 4th ( C melodic Minor over Gmaj7) = G7b13
Playing the Melodic Minor over Minor Chords
- from the Root ( C Melodic Minor over Cmin7) = Cmin/maj7
- from the b3 ( Eb Melodic Minor over Cmin7) = Cm7b5
Playing the Melodic Minor over Dominant Chords
- from the 7th ( Bb Melodic Minor over C7) = C7b9
- from the 5th ( G Melodic Minor over C7) = C7#11
- from the 4th degree ( F Melodic Minor over C7) = C7b13
- from the b9 ( C# Melodic Minor over C7) = C7Alt