The Minor Scales – Bass Clef
Along with the Major Scale, the minor scale is the most popular scale to use as a system for composing Western music.
The Natural Minor Scale can be considered a mode (a permutation) of the Major Scale; therefore, each Major scale has a Relative Natural Minor containing the same set of notes. The tonal centers and the intervals formed from their roots produce the unique sound of each scale, despite their having the same notes.
The Natural Minor
Here is a C Natural Minor Scale with its degrees and how they differ from the Major Scale.
By comparing the degrees of the Major Scale, the structure of the Minor Scale can be easily understood. The parallel Natural Minor contains all the same note degrees, but the distance from the root (1) has been decreased by one half step for the 3rd, 6th, and 7th degrees. In other words, the 3rd, 6th, and 7th degrees are “flatted” (b).
By looking at some features shared between the Major and Natural Minor Scales, we can gain some insight into their popularity for composition.
First, a comparison can be made of the intervals created with the root and other degrees of the scales. The Major Scale contains only Perfect and Major intervals from the root. Except for the root to the second interval, which is Major 2nd, the Minor Scale contains only Perfect and Minor intervals from the root.
Also, they both contain the Perfect 4th interval and the Perfect 5th Interval. Although this is true for other scales as well, the Major and Minor are unique in that the triads built off of these chord degrees are all the same quality as the chord built off the root. For the Major, this results in three Major Triads, and for the Minor, three Minor Triads. Countless compositions and entire styles are built on the sonic strength of this structure.
The Minor Scale goes a step further, and all three Perfect Interval 4-part Chords (including the Perfect Unison) are Minor 7th Chords, whereas the Major Scale has Imaj7, IVmaj7, and V7.
The Minor has two other forms (perhaps three, depending on how you look at it).
The Harmonic Minor
The first variation we’ll look at is the Harmonic Minor, which has only one note altered from the Natural Minor. That one change has a dramatic effect!
In the Harmonic Minor, the 7th note is not flatted as in the Natural Minor.
The b6 and natural 7 of the Harmonic Minor create an Augmented 2nd interval, and is the only instance of three half steps between consecutive degrees in a diatonic scale. This structure creates an exotic sound.
The chords contained in the Harmonic are obviously also altered. A surprising number of popular songs use chord progressions that come from, or at least hint at the Harmonic Minor Scale. This is probably because the natural 7th creates a Dominant 7th chord on the dominant (5th) scale tone. This has a stronger pull back to the one.
The Melodic Minor
The Melodic Minor Scale is unique in that classical composition, it ascends as a variation and then descends as the natural minor. What’s more, in Jazz improvisation, it doesn’t revert to the Natural Minor when descending, rather it stays in the variant form.
While the Harmonic Minor solved a harmonic puzzle, it created a problem melodically with the Augmented 2nd it introduced. Raising the 6th back to a Major 6th shortens this interval to a Major 2nd. This solves the melodic issue, but means that the only note that’s different from a Major Scale is the 3rd. The flatted 3rd is all that’s needed to make a type of minor scale, and you’ll learn elsewhere here that there are other minor scales, but a lot of the “minor flavor” got taken out, so playing it descending as the Natural Minor adds that flavor back in..
In the Melodic Minor as used in Classical composition, the 6th and 7th notes are not flatted as in the Natural Minor while ascending, but are flatted while descending.
In Jazz improvisation, the minor scale and its relationship to chords and key centers are distinct, and improvising requires a freer approach. So it’s played the same ascending as descending. This what I meant when I said the number of variants depends on how you look at it
In the Melodic Minor as used in Jazz improvisation, the scale does not revert to the Natural minor while descending.
Some argue that since the Melodic Minor doesn’t function in the same way in Jazz as it does in Classical, where it was developed, we’re not actually playing the Melodic Minor in Jazz, but rather the Dorian Major 7th Scale. It is also referred to as the Jazz Minor Scale.