For some musicians today, the word ‘scales’ is frightening. Ask someone who has ever taken piano lessons, they would tell you all about the trouble. If they did stop taking the classes, we can say it was one of those few reasons. But for someone making music, scales are so much more than drills, practice exercises, and warmups. They are tools for music composition. In this blog, we will decode what scales are and why they give amateur musicians such a hard time. 

Such is the importance of scales that there are dedicated applications like Scaler 2, which are designed exclusively to help them use scales better. Scaler 2 determines the key and scale one is in and suggests the chords that match the music.  

Fundamentally scales are just a collection of pitches, where each scale is curated to meet a particular purpose, therefore choosing a scale is more like choosing a tool. Different compositions demand different scales and when we get stuck on a melody, it is mostly because we chose the wrong scale. 

What are the 3 minor scales?

The three minor scales are:

1. Natural minor scale
2. Harmonic minor scale
3. Melodic minor scale

The Formulas

Key Features of the 3 minor scales

• Each of these scales are heptatonic, i.e they are each composed of seven distinct pitches before repeating.
• Each of these pitches is assigned a number, or scale degree, from 1-7 which is used to distinguish between these scales.
• Each of these minor scales contains the same first five scale degrees, which only leaves scale degrees 6 and 7 to differentiate between the three scales.

Natural Minor Scale

The intervals separating the seven scale degrees of the natural minor scale follow the pattern:

W – H – W – W – H – W – W

In tones and semitones, that is:

T – S – T – T – S – T – T

whole-step, half-step, whole-step, whole-step, half-step, whole-step, whole-step.

To build the natural minor scale, you take the major scale formula but start it on the sixth scale degree

Because of this relationship between major and minor, you can take any major scale and start it on the sixth scale degree of the scale in order to find a natural minor scale. The minor key area related to a major key in this way is known as the relative minor of the major key you’re using to find it.

For example, the relative minor of C Major is A Minor. The natural minor scale starting on A is just a C Major scale with a different starting pitch: A, B, C, D, E, F, G, A.

Following the same pattern, the relative minor of D Major is B Minor: B, C#, D, E, F#, G, A, B.

Harmonic Minor Scale

The harmonic minor scale is exactly the same as the natural minor scale with the exception of one scale degree. The harmonic minor scale features a raised scale degree 7, while the other scale degrees remain in place.

The formula for the harmonic minor scale is:

W – H – W – W – H – W½ – H

In tones and semitones, that would be:

T – S – T – T – S – T½ – S

whole-step, half-step, whole-step, whole-step, half-step, augmented 2nd, half-step.

The augmented 2nd, composed of three half-steps, is the most recognizable feature of the scale. The A Harmonic Minor scale is A, B, C, D, E, F, G#, A.

The B Harmonic Minor scale, following suit, is B, C#, D, E, F#, G, A#, B.

The prominence of the augmented 2nd leads a lot of musicians to shy away from it or to use it only very sparingly, as it will immediately change the character of a piece of music. Most of us do not follow these conventions, but it is notable that the augmented 2nd is a forbidden melodic interval in Common Practice Counterpoint.

Thus, European composition students of the 18th and early 19th centuries would have been instructed to approach a raised scale degree 7 from above and not from scale degree 6 in a minor mode.

Melodic Minor Scale

The melodic minor scale differs from the other two minor scales in two ways. The most prominent departure from the other two minor scales is in the fact that the melodic minor scale is different in its ascending form from its descending form.

The ascending melodic minor scale is identical to the natural minor scale except for the addition of raised sixth and seventh scale degrees, but the descending scale is a simple natural minor scale, meaning that scale degrees 6 and 7 each revert down a half-step in the descending scale.

The ascending A melodic minor scale is A, B, C, D, E, F#, G#, A, whereas the descending A melodic minor scale is the same as the natural minor scale: A, G, F, E, D, C, B, A.

The same pattern holds true for the B melodic minor scale, which is B, C#, D, E, F#, G#, A#, B, A, G, F#, E, D, C#, B.

General Tips For Choosing a Minor Scale

When writing melodies for pre-existing chord progressions or for Pitch Correction, the easiest way to select a scale to reference when composing your melody is to look at pitches within the chords themselves.

Generally, if the pitches of the chords fall within a particular scale, that is the scale that will inform the smoothest melody least likely to clash.

When it comes to minor scales, the fact that there is so much overlap between them means that you only have to be on the lookout for specific instances in which you might have to make a decision between your three options.

In fact, many musicians think of the melodic minor and harmonic minor scales as simple variations of the natural minor scale.

Generally, the best practice is to avoid putting raised scale degrees 6 and 7 over any chord featuring the un-raised scale degrees.

This means some pre-dominant function chords, like VI and iv, in particular, do not blend well with the ascending melodic minor scale.

It also means that the natural minor scale’s scale degree 7 tends to clash with the raised leading tone found in the dominant (V) chord. The raised leading tone found in the other two minor scales is best suited to that harmonic situation.

As noted earlier, the harmonic minor scale features an augmented 2nd between scale degree 6 and scale degree 7. The harmonic minor scale is the only one out of the three minor scales with this interval, which gives it a flavor that sets it apart from the other two minor scales.

For many musicians, it is so distinct that it has acquired something of a clichéd effect. This is not by any means to warn against its use, only to suggest that musicians be aware of connotations summoned by the sound of music.

While we have control over what we create, we do not necessarily have control over the perceptions of our audience, so we have to navigate the listening landscape as it is offered to us.

The harmonic minor scale and melodic minor scale only depart from the natural minor scale in their ascending approach to the tonic.

It is for this reason that melodies informed by these scales generally arise in dominant-function areas within chord progressions, as these are the areas most concerned with getting back to the tonic.

To sum up, The important thing to remember with any musical convention is that there are no hard and fast rules, only tools in an ever-expanding toolkit.

Melodies are not written in scales so much as informed by scales. Next time you have a melody that seems close but just isn’t quite right yet, try raising your 7th scale degree, or maybe even your 6th and your 7th scale degrees, and see what happens