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