24: Minor Scales
If you remember, in the natural minor scale, there is a whole step
between the 7th and 8th degrees of the scale. To change this to a half
step, you must raise the 7th degree a half step.
You find the key signature of a harmonic minor scale exactly the same
way as a natural minor scale: add three flats to the Major key signature of
the starting note, then simply raise the seventh degree one half step.
In the example below, I took the C Major key signature (no sharps or
flats), added three flats (Bb, Eb, Ab), then wrote out the scale and raised
the seventh degree (Bb) a half step with a natural sign.Example 24.4 The C harmonic minor scale.
There is no key signature for the harmonic minor scale, so you have to
alter the 7th degree in order to get the scale. If you tried to alter the key
signature to do this, you’d have to take out the first flat, the Bb. You can’t
take it out without also taking out the others because the order of flats
must always remain the same. It isn’t just a good idea, it’s the law.
Notice that between the 6th and 7th degree of this scale we have 1 1/2
steps. This is part of what gives the harmonic minor scale its distinctive
sound.
Play the scale in example 24.4 above. Many people think it sounds
“Arabian” or “exotic”. It’s a cool sound, and if you’re memorizing
scales, after you get your majors down, start with the harmonic minors.The Melodic Minor Scale
This is an oddball scale, one which you’ll rarely see, and rarely use, but
here it is.
The melodic minor scale is also based on the natural minor key signature
with some alterations to the notes in the scale, but not to the key signature
itself.