These are the Harmonic Minor Scale and the Melodic Minor Scale.
The Harmonic Minor Scale is obtained by raising the b7 of the Natural Minor scale by a semitone.
This means that the 7th is only a semitone away from the root note, so a melody resolves to the root much more decisively. It can have a very Turkish/Moorish sound to it.
Another reason for the use of the Harmonic Minor Scale is the change it makes to the chords. From the Natural Minor Scale the chord formed on the V is a minor chord (or minor 7th), but in the case of Harmonic Minor the V becomes a Dominant 7th chord and this has a stronger resolution back to the tonic chord.
The Harmonic Minor scale leads us to some very interesting modes. We will be looking at these and the effects the scale has on the chords built from it over the next couple of articles.
The Melodic Minor Scale is played differently when ascending and descending!
As you can see, the descending version is the same as the Natural Minor. In the ascending version the b6 and b7 of the Natural Minor are raised by a semitone. This means that the melodic push upward of the 7th to the root note of the Harmonic Minor is retained, by also raising the b6 by a semitone, the sometimes-awkward interval between the b6 and 7 is removed.
In Jazz, generally, the descending form of Melodic Minor is normally ignored and the ascending form is used for both. In fact the ascending version is often called the Jazz Minor Scale (or Jazz Melodic Minor). Again this scale gives us some interesting modes which we will investigate in the future.
Have a go at playing these variations of the Minor Scale and hear the differences for yourself!!
Until next time, work hard and have fun!!
-Duncan Richardson - MU Columnist
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