The Locrian Mode is the seventh mode of the Diatonic Major Scale. Let's look and listen to it with a bit more detail.
The Locrian mode is often described as the white keys on the keyboard from B-B'. This gives us the following intervallic series:
*w=whole step // h=half step*
The Locrian Notation Looks Like This
That's the notes B C D E F G A B' with no alterations (sharps or flats).
However, since we base a mode's scales degrees on the Major Scale, and the Locrian mode has a different intervallic series than the Major Scale, we alter the scale degrees, giving Locrian the following:
1 ♭2 ♭3 4 ♭5 ♭6 ♭7
Another way to write the scale degrees are:
- Root (as is always the case)
- Minor Second (1 semitones above the root)
- Minor Third (3 semitones above the root)
- Perfect Fourth (5 semitones above the root)
- Diminished Fifth (6 semitones above the root)
- Minor Sixth (8 semitones above the root)
- Minor Seventh (10 semitones above the root)
Note that Locrian is the only mode of the major scale that has a diminished fifth. Locrian and Lydian both have a tritone interval with the rool (6 semitones above the root), however Lydian's tritone is an augmented fourth rather than a diminished fifth.
This diminished fifth will cause problems with the utility of Locrian as we'll discuss later.
Let's listen to the B Locrian mode against a droned B:
A Quick Clarification
If you happen to be coming from the article on the Ionian Mode or the Dorian Mode, you may realize that the white keys from C-C' (Ionian) are the same notes as the white keys from D-D' (Dorian) and the white keys from B-B'.
C Ionian and B Locrian are both modes of the C Major Scale. This means that, yes, they have the same notes. But their starting points (roots) are different. And this means a lot:
- Their intervallic series are different
- Their scale degrees are different
- Their qualities (major/diminished) are different
- Their inherent chords are different
- Their functionalities are different
So even though C Ionian and B Locrian are made up of exactly the same notes, they are different! This is the beginning of modal study.
The Modal Chords Of The Locrian Mode
The Locrian mode yields one triad and one tertian seventh chord. They are:
- Diminished triad 1 ♭3 ♭5
- Half-Diminished seventh chord 1 ♭3 ♭5 ♭7
*The half-diminished seventh chord is also referred to as the “minor 7 flat 5 chord.”
There aren't really any true suspended chords since there's no perfect fifth. There are also extensions that don't really get used. Let's try to name some other chords anyway:
- Min7♭5sus4 1 4 ♭5 ♭7
Functionality Of The Locrian Mode
The Locrian Mode shows up with the vii chord in diatonic harmony. It's the Leading tone chord in diatonic harmony.
Much like the V chord and Mixolydian, Locrian's half-diminished chord has a dissonant tritone interval that wants to resolve.
Locrian's half-diminished chord has its tritone interval between the root and diminished fifth, perhaps making it “more dissonant” than the dominant chord. Because the root is arguably the most important part of the chord, having a tritone interval with it really destabilizes the chord (more so than the third and seventh interval of the dominant chord).
Because of Locrian's instability as a mode, it yields unstable chords, and is therefore not used that often. I like using the Locrian mode and its half-diminished scale as a substitution for Mixolydian and the V7 chord from time to time. Its dissonance wants to resolve up to the Ionian tonic chord.
Remember in the Mixolydian Article, we talked about the G7's tritone interval of B-F wanting to resolve to C-E. Add on a G and we have the C major triad (the tonic).
Well guess what the tritone is in B Locrian (from the C Major Scale). That's right, it's also B-F! Making it a good “dominant” substitution for resolution to the tonic.
The Darkness Of Locrian
It's interesting, in the article on Lydian (the Major Scale's brightest mode), we built it up by stacking successive fifths.
For example, F Lydian (from C Major) has the notes:
- by stacking fifths: F-C-G-D-A-E-B
- within an octave: F-G-A-B-C-D-E
Locrian (the Major Scale's darkest mode), is built by stacking successive fourths, which is the “opposite” interval of a fifth.
For example, B Locrian (also from C Major) has the notes:
- by stacking fourths: B-E-A-D-G-C-F
- within an octave: B-C-D-E-F-G-A
I talk about this more in my article Musical Light Spectrum: Brightness and Darkness.
Locrian's Characteristic Tones
When looking for a mode's characteristic tone(s) (the tones that give it its flavour and differentiate it from other modes), it's a good idea to first look at the tritone intervals and half-step intervals. It's also very important to look at the quality of the third (is it minor or major?)
Relating a mode to either Ionian (Major Scale) or Aeolian (Natural Minor Scale) can help us to determine characteristic tones as well. The reasoning here is that these two scales are so common they're almost expected. Altering them in any way peaks our attention and tell us we're in a different mode.
The Major Scale's modes each have two half-step intervals and one tritone interval.
One tritone interval could mean two tritone intervals. For example, B-F is a tritone and F-B is a tritone. Most of the time we'll look for the [one] tritone interval in the Major Scale modes.
Locrian's tritone is between its root and diminished fifth. The half step intervals are between the root/minor second and perfect fourth/diminished fifth. Locrian's third scale degree is major.
The minor third and diminished fifth tell us that Locrian has a diminished quality. The diminished fifth differentiates Locrian from all the other modes of the Major Scale.
Locrian's most characteristic tone is its diminished fifth. The instability of Locrian's diminished triad, once again, renders it “unusable as a modal centre,” some would say.
Locrian's Modal Chord
I would call Locrian's modal chord the half diminished chord, but it's more common (in minor 2-5-1 progressions) to play either Locrian ♮6 (2nd mode of the Harmonic Minor Scale) or Aeolian Diminished (6th mode of the Melodic Minor Scale).
So, in light of no better option, let's stack up our characteristic tones, looking at our half step intervals:
- minor second
- perfect fourth
- diminished fifth
It's awkward to name chords without a third and without a perfect fifth, so let's add the minor third…
1 ♭2 ♭3 4 ♭5
Perhaps better would be:
1 ♭3 ♭5 ♭9 11
A… diminished add ♭9/11 chord?
All this confusion for a mode that's rarely ever used. Sorry about that, the half-diminished chord will work just fine!
1 ♭3 ♭5 ♭7
When dealing with heptatonic modes, we can only truly get an absolutely “modal chord” when all seven of the notes are present within it. But the above chords give us a sense of the mode Locrian.
Writing And Composing With Locrian
Locrian is not really a mode that is used as a modal centre. It's quite unstable, and to most, very unpleasant to harmonize with.
That being said, it can be put to use in composition if we're striving for something strange, without much consonance.
Cadences into Locrian wouldn't give much sense of resolution since Locrian is so unstable, and so staying on the root or the root chord would probably work best for compositions in Locrian.
That all being said, there's plenty of room for experimentation and strange music, so don't let me dissuade you (I feel like I'm even dissuading myself). Go ahead and use Locrian!
I invite you to write a song based on the most difficult diatonic mode to write in: the Locrian mode! For more information, check out my article on writing and playing modally.
Chances are, even if you don't know the mode, you haven't been using it in writing and playing music.
Let me know what you come up with while writing with the Locrian mode! I bet it'll be really dissonant. And if there's anything else you'd like to add to the discussion of the Locrian mode, please leave a message in the comment section!
Related article: 5 Effective Ways To Think About The Modes Of The Major Scale
As always, thank you for reading and for your support,