These are the augmented seconds your mother forgot to warn you about! Learn all about the harmonic minor scale, harmonic minor modes, the formula to make them, and how they came to be.
Harmonic Minor Scale: Formula and Modes
There are certain things your Mom probably taught you not to do: don’t talk to strangers, don’t cross the street without looking both ways, and don’t forget to wash your hands before you eat. If she had known about augmented seconds, she probably would have warned you about those, too.Composers have gone to great lengths to set rules about what to do and what not to do when writing melodies.
If you want a good performance, you have to write a good part, and one of the things you need to watch is the intervals you use, meaning, how far apart one note is away from the next. Our ears very easily hear intervals of one half-step, or two half-steps, but an augmented second interval is three half-steps, and it causes trouble for performers.A repeating pattern of intervals within an octave is called a scale. The diatonic scales are scales that can all be played with just the white notes on the piano, and since they don’t have any augmented seconds, composers don’t have to ‘look both ways’ before using them to create melodies.
Which white note you start on will determine which scale you play, and if you start on A, you will create what is called a Natural Minor Scale:
The intervals in the Natural Minor Scale are:Whole-step, half-step, whole-step, whole-step, half-step, whole-step, whole-step.Notice that there is a whole-step between the seventh and the eighth notes of this scale. This interval bothered composers, and eventually they started to raise that seventh note a half-step so it would naturally lead into the eighth note of the scale. This is what we call a leading tone. The scale that is formed by raising the seventh note of the Natural Minor Scale up a half-step is called the Harmonic Minor Scale.
The word harmonic refers to the structure that happens under a melody. The term melodic refers to the melody itself. The Harmonic Minor Scale gets its name from the fact that composers love to use this scale to form the harmonies underneath their minor melodies. Harmonies are made up of chords, and chords are made up of intervals.To make a basic chord, you start on a given note, add the note a third above it, and then add the third above that.
A major chord has a distance of four half-steps between the first and third of the chord, whereas a minor chord has a distance of only three half-steps.There are three chords that are fundamental to harmonic structure, and those are called the tonic, which is a chord built on the first note of the scale, the subdominant, which is built on the fourth note of the scale, and the dominant which is built on the fifth note of the scale. This is how these three chords look in the A Natural Minor Scale.
Notice in the example above that the dominant chord in the A Natural Minor Scale is a minor chord. This is the thing that bothered composers the most.
They really wanted to use a major chord as the dominant chord because it contained that leading tone that naturally lead to the tonic. That is exactly what they got when they started using the Harmonic Minor Scale:
Remember your Mom telling you to be careful what you wished for because you might get it? Well, that is exactly what happened to these composers who wanted that raised leading tone. When they raised the seventh note in the scale, they created a problem between the sixth and seventh notes of the scale, which was none other than the dreaded augmented second interval. Notice that the distance between the sixth and seventh notes of the harmonic minor scale is three half-steps. The raised leading tone made this scale great for writing harmonies, but not so great for writing melodies.
Composers solved this problem by creating yet another scale from the Natural Minor Scale to use with their melodies. They called it the Melodic Minor Scale, which became the standard for minor melodies. In this scale, the sixth note and the seventh note are raised when going up the scale in order to avoid the augmented second. On the way down, both are lowered to return it to the natural minor.
Formula for the Harmonic Minor Scale
The Harmonic Minor Scale can start on any note, but has to have these intervals in this order:Whole-step, half-step, whole-step, whole-step, half-step, three half-steps, half-step
Harmonic Minor Modes
Just as you can create different diatonic scales by starting a scale on different white notes on the piano, you can create different Harmonic Minor Modes by starting a scale on different notes of the Harmonic Minor Scale:
Please note that the use of these Harmonic Minor Modes is not extremely common, and the names of the modes are not standardized, so you may see variations of these names in use.
When the seventh note of a Natural Minor Scale is raised a half-step, the resulting scale is called the Harmonic Minor Scale. This scale is used primarily for the harmonic structure of music in minor keys because it provides a major dominant chord. This scale is used less frequently for melodies because of the augmented second that exists between the sixth and seventh notes of the scale. The Melodic Minor Scale, which eliminates the augmented second, is more often used in creating minor melodies.
The Harmonic Minor Modes, which can be created by starting on different notes of the Harmonic Minor Scale, are not very common, but are in use today.