Melodic minor · The minor scales · Music theory
To avoid that augmented 2nd in melodies, melodic minor also raises VI on the way up: F♯ and G♯ in A minor. On the way down the leading tone no longer has…
Melodic minor
To avoid that augmented 2nd in melodies, melodic minor also raises VI on the way up: F♯ and G♯ in A minor. On the way down the leading tone no longer has to rise, and the scale goes back to the natural form.
This is the traditional form, the one asked for in exams. In jazz the ascending form is also used in both directions.
The melodic form in practice
The rule of going up one way and down another is a teaching simplification. What really decides is the path of the melody: VI rises when it heads for the leading tone and VII falls when it moves away from the tonic. So raised notes can appear going down, or natural ones going up, depending on where the phrase is going.
These notes also change the chords: with VI raised, IV in minor becomes major and II, minor. In A minor, D–F♯–A and B–D–F♯ appear naturally in a melodic passage.