The Harmonic Minor scale was created for Harmonic reasons. The Natural Minor Scale or Aeolian mode yields the following chords when harmonized in the key of A Minor:
- A minor . B diminished . C major . D minor . E minor . F major . G major
The V chord in Natural minor is a rather passive sounding E minor which does not provide a very satisfying resolution to the I chord because it has no leading tone of G# pushing toward the tonic. Since chords come from scales a correction in the scale of A Natural Minor to accomodate this leading tone and strong movement toward the I chord requires raising the VII degree of the scale:
- A . B . C . D . E . F . G# . A = Harmonic Minor Scale
By raising this VII degree it creates the interval of an augmented 2nd between the 6th and 7th degrees of the scale which creates a rather middle eastern quality which may not always be desirable “melodically” , however this raising of the 7th degree does provide the leading tone to the tonic chord which at the same time creates a major or dominant 7th chord as the new V chord:
- V chord – E – G# – B = Major or V7 – E – G# – B – D
The complete harmonization of the Harmonic Minor Scale in the key of A would be as follows:
- A minor . B diminished . C augmented . D minor . E7 (maj) . F major . G# diminished