In the first lesson, we learned the major scale and how to name intervals. In the second lesson, we learned how to build chords based on the major scale. In this lesson, we'll learn about the three minor scales.
The three minor scales are called as follows: the melodic minor scale, the harmonic minor scale, and the natural minor scale. I will address each one individually, explain why they are called what they are, how they are used historically, and what sweet new chords can be learned from them. But before I do that, we must know how minor scales relate to major scales.
Most music has a key, be it major or minor. When written on sheet music, these keys are indicated by the key signature - which is to say, the sharps and flats that go over the lines. These indicate which notes are in the key (for example, G major has one sharp - F#. The # goes on the F line. Makes sense, right?)
The reason I mention this is because, the term "relative key", "relative major", "relative minor", "parallel major", "paralllel minor", and "parallel key" will be used in this lesson.
A relative key is when a different key shares the same key signature. (C major and A minor, for example.)
A relative major is when that key is major. (C major is the relative major of A minor.)
A relative minor is when that key is minor. (A minor is the relative minor of C major.)
A parallel key is a different key based on the same root note. (A minor and A major are parallel keys.)
A parallel major is when that key is major. (A major is the parallel major of A minor.)
A parallel minor is when that key is minor. (A minor is the parallel minor of A major.)
With that out of the way, we can dig in. First off, the natural minor scale. In the key of A minor in one octave, it looks like this:
In the key of A minor, these notes are, A B C D E F G A. This is the simplest minor scale to understand, as its origins are... natural. What I mean is, the natural minor scale has the same key signature as C major. It effectively is the C major starting on A. (To more advanced students, this means it is also the same as A Aeolian... but that's a different lesson.) The natural minor scale has the same notes as the major scale of its relative major.
The pattern we used to form the major scale, Whole Step Whole Step Half Step Whole Step Whole Step Whole Step Half Step? That same pattern, starting at a different point, is the natural minor scale. (Whole Step Half Step Whole Step Whole Step Half Step Whole Step Whole Step.)
The intervals that make up the natural minor scale are the Root, Major 2nd, minor 3rd, Perfect 4th, Perfect 5th, minor 6th, minor 7th, and then octave and so forth. How did it come to be and what is its purpose? More on that in a second. Secondly, the melodic minor scale. In the key of A minor in one octave, it looks like this:
You may notice this starts out the same way as the natural minor scale, but ends the way its parallel major scale would. In the key of A mior, the notes making up the melodic minor scale are A B C D E F# G# A.
The intervals that make up the melodic minor scale are the Root, Major 2nd, minor 3rd, Perfect 4th, Perfect 5th, Major 6th, Major 7th, and then octave and so forth. SO why are the natural minor and melodic minor scales called as such, and how are they related? In classical music, the natural minor scale and the melodic minor scale are the same scale. Huh?
You see, in classical music, the melody almost always ends with the major 7th going up to the root ("Ti - Doe" if doeing a deer is your scene.) This is true even in minor keys, but jumping from a minor 6th to a major 7th sounds awful (as you'll see in a bit.) Because of that, in classical music, the scale played up is the melodic minor scale, and the scale played down is the natural minor scale. Some guitar teachers will lightly acknowledge this, and say such silly things as "Melodic minor ascending" for the melodic minor scale as I just showed it and"melodic minor descending" for the natural minor scale.
In a lot of jazz music, people will player the melodic minor scale as I showed it both up and down (so if you have one of those silly teachers who uses the term "melodic minor ascending", you can play the ascending scale even descending. Oddly stupid, right?)
So that's WHY those scales are the way they are. And it should also give you the idea behind the names: the natural minor scale is called such because it doesn't change the key signature, and the melodic minor scale is called such because it changes the scale for the melody.
So what is the harmonic minor scale and why is it called that? In the key of A minor in one octave, the harmonic minor scale looks like this:
The intervals that form the A harmonic minor scale are the Root, Major 2nd, minor 3rd, Perfect 4th, Perfect 5th, minor 6th, Major 7th, and then octave and so forth. Remember when I said jumping from the minor 6th to the Major 7th sounds awful melodically? Just trying play that part over and over for a bit.
It sounds unusual, and kinda cool in a way... but as a scale to just go up and down? Yuuuck. The harmonic minor scale literally exists only so pianists can practice chords. What?
You heard me. It has become a gimmick in certain situations with soloing, and has its own place now that we're in the year 2012 and that melodic jump that irks me has become more acceptable to the modern ear. But in terms of historic origins, the harmonic minor scale exists so that pianists can play all the common chords in minor keys without changing scales.
So in my second lesson, we learned that the diatonic chords of a major scale were I, ii, iii, IV, V, vi, vii. Because there are a wide array of different intervals in the minor scale in the classical sense (between melodic minor and natural minor, you have major 6ths and minor 6ths and major 7ths and minor 7ths), one can form a ton of different chords. But the most common chords based on each root note appear in the harmonic minor scale, and that's why it exists.
Thus, the chords of A harmonic minor are:
i (A C E in A minor. That shouldn't be surprise anyone.)
ii (B D F. A diminished chord!)
III+ (C E G#, )
iv (D F A, the minor four.)
V (E G# B. This is why the G# is really there: the V chord goes to i in classical music, and the G# makes it a V.)
bVI (F A C.)
#vii (G# B D)
With minor scales, with roman numeral naming, we must also indicate what note the sixth and seventh chords are based on. This is to say, even though the harmonic minor scale shows the most common harmonies, it's possible to build a chord based on the minor 7th of the natural minor scale... so we must say #vii or bVII, rather than just saying "vii" or "VII" like we could with the major scale.
And just as a little extra tidbit: if you recall in my second lesson, I said there were four types of diatonic chords, but I only displayed three in the major scale. The fourth kind was the augmented chord: A Root, a Major Third, and an Augmented 5th. C E G# in A minor. Look at the harmonic minor scale, and then the third chord. You now have the only diatonic example of the fourth kind of triad.
So that's your minor scales. My next lesson should be about chord functions, and finally getting into how the theory works and what its uses actually are, rather than just clearing the air on common misconceptions.
If you want a lesson on anything in particular, just comment or ask for it! I hope to be writing lessons for UG for a long time. It would be sweet to get the UG writing job.