Natural Minor vs Harmonic Minor
The harmonic minor scale is the same as the natural minor but with a raised seventh degree. So in the natural minor we have a minor seventh and in the harmonic minor we have a major seventh:
C Natural Minor Scale:
C Harmonic Minor Scale:
What’s The Deal?
You may be wondering how and why we use all of these different minor scales and this is where chords and tonality come into play.
Let’s look at a simple chord progression in C major: C Major – G Major – C Major
This is chord 1 to chord 5 and back to 1. We can see this in our list of chords in the C Major key:
- Chord 1 – C Major
- Chord 2 – D Minor
- Chord 3 – E Minor
- Chord 4 – F Major
- Chord 5 – G Major
- Chord 6 – A Minor
- Chord 7 – B Diminished
That movement of chord 5 to 1 is one of the most important progressions in music. The Perfect Cadence.
The reason for this strong feeling of resolution back to chord one is down to the scale degrees of our key in those chords. Let’s look at the scale degrees in each chord:
Chord I – 1 3 5
Chord V – 5 7 2
The seventh degree used in chord 5 leads nicely back into the tonic note. The B resolves to C in the key of C major.
Chords Of The Minor Key
Now let’s look at the chords we can generate in the Minor key using the Natural Minor Scale:
- Chord 1 – C Minor
- Chord 2 – D Diminished
- Chord 3 – Eb Major
- Chord 4 – F Minor
- Chord 5 – G Minor
- Chord 6 – Ab Major
- Chord 7 – Bb Major
Notice how the Chord 5 is Minor. Our 1-5-1 progression becomes: C Minor – G Minor – C Minor
The chord 5 to 1 progression here has less pull because the third of the G minor chord is Bb. It doesn’t lead as well into C.
By switching the chord 5 to Major we get a greater pull to the chord 1: C Minor – G Major – C Minor
When we change the chord 5 to Major we are raising the 7th degree of the key. In C Minor, the Bb becomes B. This gives us a C Harmonic Minor scale!
So all of this is the reason behind our use of the harmonic minor scale. It’s called the harmonic minor because it’s a consideration of the harmony of the tune. The chord progression. This can be anything from implied harmony through a single melodic line through to full chords or polyphony played by an ensemble.
Harmonic Minor Example
As well as straight chords, you’ll also hear the scale in melodies as they outline the harmony. Here’s a simple melody working through chords 1-5-1. C Minor – G Major – C Minor:
If we used the C Natural Minor scale for our minor key, the second bar would be a G minor chord using the Bb:
The harmonic minor is an artistic choice and was incredibly popular in music of the baroque and classical periods. But even though it has a very neoclassical sound when played as a scale in isolation it’s still used in countless tunes today.
If you’re in a minor key and making use of a major or dominant 7 as chord 5 then there’s a good chance you’re employing the harmonic minor. It’s won’t necessarily be a conscious decision. It’s simply a result of the harmony.
Many tunes will actually switch between the different scales as a consequence of the harmony in use. The following line descends through the natural minor during chord 1 (bar 1) before switching to the harmonic minor scale on chord 5 (bar 2):
Remember that even though it appears to be a purposeful switching of scales in the melodic sense, we’re actually just outlining the chords. It’s a chordal consideration expressed through the melody.