The melodic minor scale is a variation of the harmonic minor scale with a raised 6th in addition to the raised 7th. It’s used more often in jazz and classical music than in rock, and its formula looks like this: 1-2-f3-4-5-6-7. It’s also thought of as a major scale with a flattened 3rd or a Dorian scale with a raised 7th.
In classical theory, this scale has an ascending and descending form. They say that you’re supposed to play the raised 6th and 7th while ascending the scale but play all natural minor scale degrees while descending the scale. However, this is not how modern musicians use the scale. Instead, they use the raised 6th and 7th degrees in both directions.
You can use this scale over V7 chords in a minor key just as you do with harmonic minor.
An example of this scale is the Christmas song “Carol of the Bells,” which uses the natural minor scale over most of the chord progression but changes to melodic minor over the V7 chord. Another example is “Yesterday” by The Beatles, which uses part of the D melodic minor scale over the Em-A7-Dm chords during “all my troubles seem so far away” (guitar tuned down one whole step to D).
