How is the harmonic minor scale defined?

The harmonic minor scale is defined as a minor scale that features a raised seventh scale degree. This alteration is significant because it creates a leading tone that resolves up a half step to the tonic, enhancing the harmonic tension and providing a stronger resolution back to the root note.

In terms of scale degrees, the steps of the harmonic minor scale are: whole step, half step, whole step, whole step, half step, augmented second (which results from the raised seventh), and half step. This structure is what differentiates the harmonic minor from the natural minor scale, where the seventh scale degree is not raised.

Understanding the significance of the raised seventh is crucial in musical contexts, especially in Western classical music, where it often leads to dominant chords and resolves into tonic chords effectively. The other scale modifications, such as altering the sixth or third degrees, do not define the harmonic minor scale but relate more closely to other minor scale variations, which is why they do not represent the essential characteristic of the harmonic minor scale.