Introduction
Minor tonality is a topic which confuses many
musicians,
music students, and people in general. A lot of people don't know what the point of all the different minor scales is, and what the harmonic and melodic minor are good for, or indeed, where did they come from. How do you know which minor scale to use and when? And what's with that whole difference between
ascending and
descending in the
melodic minor? And wait one second, I thought there was only one "minor scale", what's all this talk of many? So I think it's about time I made some sense in the mess that is minor scales.
Definition
'Minor scale' can mean one of two things:
- A minor scale is a scale which outlines a minor chord (the definition I will use)
- Another term for the natural minor scale.
This is confusing, but such is life. The 'main' minor scale is the natural minor scale. Music written in the minor scale is usually written using the natrual minor scale. This is true for
all pre-20th century Western music. So, if someone tells you to play the C minor scale, they want you to play the C natural minor.
However, even thought "the" minor scale is the natural minor, no one will argue with you when you say that the harmonic minor scale is a minor scale or that the Dorian scale is a minor scale. That is why we need to know that there are many minor scales, and yet understand that many people use the term "minor scale" for the natural minor scale).
What is a minor scale?
Now that we've gotten that out of the way, let us focus on what a minor scale is. Well, again, there are different views on it, and I'll mention another view, but focus on the one that I think is most
productive (not necessarily the 'correct' one, but the one which captures the essence of the minor scale.
A minor scale is a scale which outlines a minor chord. All that follows in small letter is a bit of 'musical philosophy', and is not relevant if you are not extremely well versed in music theory or if you agree with me thus far. If it gets a bit complicated/boring, ignore it.
Some people will say that a minor scale is one which has a minor 3rd in it (making it minor). Also, chords with a minor 3rd are minor, including minor7b5 (which is a minor 7th chord with a flatted fifth). This is a bit problematic, so I won't use this definition. Why is it problematic? First, the m7b5 chord is built upon the diminished triad, not the minor triad, so it doesn't have the basic minor sound. Second, it poses problems for scales like the altered scale, which is obviously not a minor scale, but has a minor 3rd. And there are other problems I won't get into as this is not the main topic of this writeup.
Basically, a scale outlines a minor chord if it has a b3 and a 5. So C minor is C Eb G and any scale with these 3 notes is a minor scale. For example:
C natural minor - C D Eb F G Ab Bb C
C harmonic minor - C D Eb F G Ab B C
C Phrygian - C Db Eb F G Ab Bb C
Natural Minor
Like I said in the first part, the natural minor is THE minor scale. It is the 6th mode of the
major scale.
(Note - just like minor scales, there are several major scales. When you say "major scale", you are referring, naturally, to the Ionian mode, i.e. in C - C D E F G A B C). So if C major is C D E F G A B C, the corresponding natural minor is A minor -
A B C D E F G A. The natural minor scale has the same
key signature as its corresponding major scale. Eb major has 3 flats, so it's corresponding minor, 1 1/2 tones down, C minor has 3 flats too -
Bb, Eb and Ab. Easy.
The natural minor is the sound our ears associate with the minor key - it has a flat third, flat sixth and flat seventh. Compare C major and C minor:
C major - C D E F G A B C (1, 2, 3, 4, 5, 6, 7, 8)
C minor - C D Eb F G Ab Bb C (1, 2, b3, 4, 5, b6, b7, 8)
In brackets, I put the relationships of the notes to the root, This will help you compare between the different scales. (Note which you might want to ignore - the relationship to the root is actually also the interval. So A is a major sixth from C, and is marked by "6". Eb is a minor 3rd from C and is marked by b3. A G# under this system would be marked #5, etc).
Harmonic Minor
So although the natural minor scale is the "perfect" minor scale, in as much as to our ears it sounds perfectly minor, it has a serious "flaw". I use the term flaw very loosely here. Much music is written in the minor key and sounds absolutely beautiful. For example, much
Irish music is written in the natural minor, and it's terrific. But Western music relies on
dominant chords. And on the
leading tone. The leading tone is the tone half a tone below the root. So in C major, B is the leading tone. A quick look at the natural minor scale shows us there is no leading tone. This means we cannot have a dominant that resolves to the tonic. (Quick explanation - most Western music ends in a dominant chord resolving to the tonic. In C major - G7 is the dominant chord, and so most music in C will end in G7 - Cmajor (or G - C))
The fifth mode of the minor scale is also minor (Gm in C minor), which means poses a serious problem. We don't have a dominant chord. What to do? What to do? We need a leading tone? Let's make a leading tone! Change the Bb to a B. Problem solved. We now have a leading tone, we have a dominant chord that resolves to the tonic. No problem. I present the harmonic minor scale:
C harmonic minor - C D Eb F G Ab B C (1, 2, b3, 4, 5, b6, 7, 8)
The harmonic scale gets its name from the fact that it solves a harmonic problem, and it differs from the natural minor by only one note. Looking at it you can see that it has a leading tone, and also, the chord formed upon the fifth note is a dominant chord, G7 (G B D F) in our case.
Melodic Minor
Problem solved. So let's use the harmonic minor scale. Well, here we have another problem. Between the sixth and seventh notes of the scale we have an
augmented second. This poses a
melodic problem, as Western music is written primarily using
steps, i.e. major and minor seconds. Although this step is a "second", it sounds like a
minor third, which is a very large step, and Western music dictates that it is not a step. Basically, we can't write melodies using this scale.
Of course we can write melodies in this scale, just like we can have harmonies in the natural minor scale. Much Jewish music is written using the harmonic minor scale. But this isn't about Jewish or Irish music, it's about Western music. Deal. In order to be able to write melodies, we can raise the sixth note of the scale. So we have:
C melodic minor scale - C D Eb F G A B C (1, 2, b3, 4, 5, 6, 7, 8)
Problem solved. So let's use the melodic minor scale. The problem is that although we did indeed solve both problems, i.e. we can write melodies and we have a leading tone, it now sounds too much like the major scale! The only difference between the melodic minor and the major scale is one note! This is a serious problem.
So we need to use the natural minor if we want to sound "minor", and the melodic minor if we want to have a leading tone in our melodies.
Basically, we want both, and you can see that we need the natural sixth and seventh (in the melodic minor, as opposed to flat sixth and seventh in the natural minor) only in melodies when we want the leading tone, and only when we are ascending. Lets' look at the following melody, written using the melodic minor: C B A G F A G B G. This does not sound minor, and we have no real "reason" for the melodic minor as we are not using the leading tone as such, so we can use the flatted sixth and seventh (i.e. C Bb Ab G F Ab G Bb G C), which sounds much more minor. But look at the following case, when we DO use the meodic minor to good effect, without losing the minor sound - C Eb C Bb G Ab F G A B C. This still sounds minor, and also has a leading tone and so is all dandy. This is the reason that in classical music, the melodic minor scale is often C D Eb F G A B C when ascending, and C D Eb F G Ab Bb C when descending. In jazz, there is no difference between ascending and descending.
Other Minors
There are two other important (Western) minor scales: the
Dorian scale and the
Phrygian scale.
Of course there are some others, like the Dorian b9 aka Phrygian natural 6, which is the second mode of the harmonic minor scale, but they are rarely used.
The Dorian scale is C D Eb F G A Bb C (1, 2, b3, 4, 5, 6, b7, 8)
The difference between it and the natural minor is that the sixth is raised in the Dorian. The Dorian scale is the second mode of the major scale, and is used often in II-V progressions. In general, it is the scale of choice for improvisors in jazz music, as there are no avoid notes (well, the 6th is a color avoid, but it gives the Dorian scale its sound, and so is used freely). In general, unless the aeolian (or natural) is specified, as in Milestones, for example, the Dorian will be used.
The Phrygian scale C Db Eb F G Ab Bb C (1, b2, b3, 4, 5, b6, b7, 8)
As you can see, the difference between the natural minor and the Phrygian is the b9 (or b2). This gives the Phrygian a "problematic" sound, as the b9 is an avoid note, as is the b13 (b6), which means that this scale will not be played unless specifically called for in jazz, for example in Chick Corea's La Fiesta, or Carla Bley's Vashkar. But the Phrygian scale is most commonly found in spanish music, most notable in flamenco, and in fact it gives the flamenco its distinctive sound.
Pentatonic minor scales
A minor pentatonic scale is one which outlines a minor chord, and the most common is the
minor pentatonic scale, which is called that because it is the most common minor pentatonic scale (very similar to that whole discussion at the top).
The minor pentatonic scale is C Eb F G Bb (1, b3, 4, 5, b7)
This scale is used extensively in rock music, and in blues.
That's all the major stuff (small pun there) about minor scales that I can think of, but I'll leave you with one small extra tip for jazz improvisors. Another minor pentatonic scale is the minor 6th pentatonic scale: C Eb F G A (1, b3, 4, 5, 6). This is cool because you can play it on minor chords, but also works really nicely on a dominant chord which requires the altered scale. So on B7alt, you can play the C minor 6th pentatonic scale, giving you C (b9), D# (3), F (b5), G (b13), A (b7), all the important notes of the altered scale in one easy pentatonic.
Summary of all the important minor scales in Western music - for ease of reference. (In A, for no particular reason).
Natural minor (Aeolian) | A B C D E F G
|
Harmonic minor | A B C D E F G#
|
Melodic minor | A B C D E F# G#
------------------------|------------------------
Dorian | A B C D E F# G
|
Phrygian | A Bb C D E F G
|
Dorian b9 (Phrygian n6) | A Bb C D E F# G
------------------------|------------------------
Pentatonic minor | A C D E G
|
Pentatonic minor 6 | A C D E F#