A major scale that never got over its lowered third.
The Scale
The melodic minor is the classical solution to a problem the harmonic minor created. Raising the seventh degree of natural minor gave harmony its leading tone but left an awkward augmented-second leap in the melody. So composers raised the sixth degree too, smoothing the ascent into a graceful line of whole and half steps. The result, going up, is a scale that is a major scale with a single alteration — a flattened third. Traditionally the melodic minor descends as pure natural minor, restoring both the flat sixth and flat seventh, which is why it is sometimes called the scale with two faces. Modern jazz theory ignores the descent entirely and treats the ascending form as a scale in its own right.
Structure
| Attribute | Value |
|---|---|
| Notes (from C) | C D E♭ F G A B (ascending) |
| Interval formula | W H W W W W H |
| Number of notes | 7 |
| Defining feature | Minor with raised 6th and 7th ascending; a major scale with a flat 3rd |
Character
Because only one note separates it from the major scale, the melodic minor sounds bright, poised, almost optimistic for something called minor. The flat third supplies just enough shadow to keep it from tipping into cheerfulness, while the raised sixth and seventh give the ascending line a forward lean, an eagerness to arrive. It is a subtle, sophisticated colour — less overtly dramatic than harmonic minor, more ambiguous, harder to pin to a single mood.
In Practice
Its classical home is the ascending melodic line in minor-key writing from the Baroque onward. In jazz it is a workhorse: the ascending melodic minor generates a whole family of useful modes, most famously the altered scale played over dominant seventh chords, making it indispensable to bebop and modern improvisers reaching for tension over a turnaround.