Is Locrian a minor mode or is it a diminished mode?

Question

I have heard 2 different schools of thought when describing the Locrian mode. The first one that I heard several years ago, when I first heard about modes is that it is a minor mode, despite its diminished 5th because its tonic is the seventh degree of the major scale and the seventh tends to have a diminished quality, especially in minor.

Now I hear more people saying that it is not a minor mode, it is its own mode, a diminished mode.

Here is the first school of thought that I heard:

MODE        QUALITY
----        -------

Lydian      MAJOR

Ionian      MAJOR

Mixolydian  MAJOR

Dorian      minor

Aeolian     minor

Phrygian    minor

Locrian     minor

This one kind of makes sense because Locrian is a modified minor scale.

And here is the more current school of thought that I keep hearing:

Mode        Quality
----        -------

Lydian      MAJOR

Ionian      MAJOR

Mixolydian  MAJOR

Dorian      minor

Aeolian     minor

Phrygian    minor

Locrian     diminished

This one implies that the modes are incomplete, at least to my eyes it does. To my eyes, this means there should be 3 diminished modes and 3 augmented modes just like how there are 3 major modes and in this school of thought, 3 minor modes. Also, the only connection between Locrian and the Diminished Scale is that the tonic triad is diminished in both cases. The Diminished Scale goes further than Locrian because the only triad you can make out of the Diminished scale, with each note being 2 scale degrees away is a diminished triad. To my eyes, basing the classification of the modes on the tonic alone as in the school of thought that says that Locrian is a diminished mode is not right. I would say that Locrian is a minor mode because it is based off of the minor scale.

But what do you think? Do you think Locrian is a diminished mode and not a minor mode? If so, why?

Answer 1

The locrian mode is not a minor mode. If its a mode at all it would be a diminished mode. (If I’m not wrong someone has recently posted a piece in locrian mode, was it by Skriabin? I’ll have to look up later.)

This one implies that the modes are incomplete, at least to my eyes it does.

As you say the modes are incomplete. So the Aeolian and Ionian mode have been added to complete the modes. However the locrian was only a theoretical construct derived of the doremi scale.

The following text is a translation of wiki (German)

From the sixteenth-century added modes of Ionian and Aeolian today's major and minor emerged. The ionic scale is thus identical to the major scale, the aeolian scale to the natural minor scale.

In the locrian mode there is not a characteristic difference interval to major or minor. In order to turn a minor scale into a locrian you have to lower two levels, namely the second and fifth.

There has never been a Lokrian mode in the system of Church tones. The name comes from the music theory of Greek antiquity, where she played a never quite clarified, more peripheral role. Only recently, under the old name, was a new ("locrian") mode invented to complete the system for practical purposes.

The lokrian scale differs from the others in that above the root note, a diminished fifth (tritons ), which is why it used to be considered useless.

Nevertheless, in jazz it enjoys a certain improvisation scale of some popularity.

https://de.wikipedia.org/wiki/Modale_Tonleitern

English wikipedia is identical:

The Ionian mode corresponds to the major scale. Scales in the Lydian mode are major scales with an augmented fourth. The Mixolydian mode corresponds to the major scale with a minor seventh. The Aeolian mode is identical to the natural minor scale. The Dorian mode corresponds to the natural minor scale with a major sixth. The Phrygian mode corresponds to the natural minor scale with a minor second. The Locrianis neither a major nor a minor mode because, although its third scale degree is minor, the fifth degree is diminished instead of perfect. For this reason it is sometimes called a "diminished" scale, though in jazz theory this term is also applied to the octatonic scale. This interval is enharmonically equivalent to the augmented fourth found between scale-degrees 1 and 4 in the Lydian mode and is also referred to as the tritone.)

But in this link you’ll find a lot more interesting information about the modes:

https://en.wikipedia.org/wiki/Mode_(music)

Answer 2

Depends how you define a 'minor' mode. Most of the modes contain a major or minor third and a perfect fifth and so may be considered as modifications of either the major or minor scales. The perfect fifth allows a dominant-tonic interaction, very useful when writing any sort of functional harmony. It defines where 'home' is.

Locrian doesn't have a perfect fifth. (Which is probably why it is rarely found in the wild, outside a textbook.) It certainly isn't a 'major mode'. If we can excuse the lack of a dominant, we can class it as a minor one. If not, it needs its own category.

Be aware of the reasons to class it as a 'minor mode' or not. Then stop worrying. It's only a label. There's no 'correct' answer.

Answer 3

I keep coming back to this statement of yours:

This one implies that the modes are incomplete, at least to my eyes it does. To my eyes, this means there should be 3 diminished modes and 3 augmented modes just like how there are 3 major modes and in this school of thought, 3 minor modes.

I think this is just your expectation, not how the system really works. A diatonic scale is made up of 7 notes, so by the definition of what the modes are, there can only be 7 of them. According to Wikipedia:

Modern Western modes use the same set of notes as the major scale, in the same order, but starting from one of its seven degrees in turn as a tonic, and so present a different sequence of whole and half steps.

Everything I'm going to say from here on is pure speculation and not accepted music theory. I'm just thinking out loud here. Please don't take is as fact; it's just a possible line of experimentation

If you wanted to have a scale with 9 modes, 3 of each minor/major/dim, you would need a scale with 9 notes. How would you create that? Well, the C ionian / F lydian scale is constructed by starting on an F and going through the circle of 5th a total of 7 times (6 jumps):

F - C - G - D - A - E - B

Which you can sort into our beloved C ionian.

If you wanted a 9-note scale, all you need to do is add 2 extra jumps, yielding:

F - C - G - D - A - E - B - F# - C#

Now, this gives us 2 extra modes, starting at F# and C#. I'm going to give them some arbitrary names:

• Achaean: F# - G - A - B - C - C# - D - E - F
• Kalamatan: C# - D - E - F - F# - G - A - B - C

These 2 modes behave in a funny way:

• The Achaean is at the same time minor (with a perfect 5th) and diminished.
• The Kalamatan is definitely diminished, but either with a major or minor third.

So you could derive 2 dimished modes out of this if you wanted, giving you the 3 dimished modes that you were expecting. Of course, the other modes could potentially be revised and reclassified. This also begs the question of how do you count 3rds or 5ths given that you have some new chromatic notes in-between.

Another way to study this could be to take a scale with more notes (perhaps 17-TET), choose a subset of 9 notes and play with the resulting modes.

Perhaps it could be worth experimenting with 9-note scales and see where this takes us?

Answer 4

I only know of the modes being divided up into major or minor based on the third scale tone.

Locrian is not one of the traditional, Medieval modes. It's a modern concept of taking all modes, or rotations, of the major scale.

About 3 diminished modes, etc.

If you keep the tonic fixed, you can move through the modes by adding flats by perfect fifths. Starting with a tonic C and adding five flats we eventually arrive at locrian...

Locrian
Order of flats:    4  2    5  3  1
Scale degrees : 1 b2 b3 4 b5 b6 b7 1

...but if we add one more flat, it will be applied to the tonic!

(One more flat after locrian, Cb lydian, Gb major) Order of flats: 6 4 2 5 3 1 Scale degrees : b1 b2 b3 4 b5 b6 b7 b1

You only get seven diatonic modes per tonic and then the tonic changes. 3 major + 3 minor + locrian.

I would say that Locrian is a minor mode because it is based off of the minor scale.

All of these modes are based off the diatonic gamut of pitches ABCEDFG. Sometimes they are called the Medieval or Church modes in reference to their historic origin. Jazz and popular styles use them too, but not in the historic way, nevertheless their origin in still the same. Grouping them into major and minor highlights their respective tonic chords and also excludes the odd ball, historically unused locrian mode. Actually, at a certain historic point only four modes were used - dorian, phrygian, lydian, and mixolydian - along with their plagal forms for a total of eight diatonic modes. Also, for what it's worth, when the modes are used in counterpoint or harmonically, they aren't purely diatonic. Accidentals are used to create leading tones and avoid certain diminished intervals.