harmonic minor scale
A minor scale with a raised seventh degree, creating a leading tone and an augmented second between degrees 6 and 7
In Depth
The harmonic minor scale modifies the natural minor by raising the seventh degree by a semitone, producing a leading tone that enables authentic (V–I) cadences. The resulting augmented second between the sixth and seventh degrees gives the scale an exotic, Middle Eastern character. This augmented second was considered an awkward melodic interval, which led to the development of the melodic minor scale. The harmonic minor is essential for understanding chord construction in minor keys, particularly the dominant triad and diminished seventh.
The augmented second in the harmonic minor is the same interval found in many Middle Eastern scales, which is why classical music in harmonic minor can sound vaguely exotic.