The Locrian Distinctive
Updated: May 18, 2021
Continuing our Quick & Dirty approach to the modes by backdooring in from a scale you're most likely to know; the Minor Pentatonic. Here are two Minor Pentatonic Scale patterns; one with a 6th-string root, and one with a 5th-string root:
The number of each note is based on the notes of the Natural Minor Scale (don't worry about whether you know it or not). As you can see, there are two notes missing; the 2nd and the 6th.
You should drill the above two patterns in every key around the Circle.
If you don't know what I mean by, "around the Circle," stop right here and download the 5-Lesson Foundational Series. This series of lessons teaches the Circle of Keys as an organizational mechanism by which you ensure that whatever you learn is drilled in every key in all possible positions. It also gives you a method to find any note, anywhere, without memorizing note names on every string. That is a beautiful thing!
You can download the 5-Lesson Foundational Series right here for free with no further obligation or commitment:
Commensurate with the Quick & Dirty concept we're going to simplify things even more by only dealing with the upper octave, which is where most of the soloing activity occurs:
The Locrian Mode is probably the least used of the 7 modes of the Major Scale. In-and-of itself (which is how we're approaching each tonality) it has an unresolved, dark and unsettled quality. Plus, the corresponding chord over which it is most often used (the Half-Diminished chord) is one that is not commonly known among beginning and intermediate players.
Be that as it may, the distinctive aspect of the Locrian sound is a diminished (flatted) 5th. So all we have to do is flat the 5th of the Minor Pentatonic patterns above:
Note: I've included the flat-5 in the lower register because it's very accessible and I use it often.
There is an alternative location for the higher of the flat-5s in the above patterns:
Now before we get into the context in which the Locrian is used, I need to discuss the reasons why this sound is so specialized and the resulting confusion among beginning and intermediate players concerning its use. It's not a common sound in popular music.
First of all, the flat-5 is indeed used in the Blues all the time. Adding the flat-5 to the Minor Pentatonic scale is commonly taught as the "Blues Scale" and can be found all over the interweb thingy. I don't use the term, "Blues Scale" when teaching this concept (a minor pet peeve of mine - I'll spare you the rant!), I simply refer to it as a "passing tone" and leave it at that.
The point is, in that situation, you have not replaced the perfect 5th with the flat-5, you have added the flat-5 to the scale. Your scale contains both the diminished 5th and the perfect 5th. The b5 is dissonant and demands resolution. Many times it will resolve upward to the perfect 5th - thus, "passing tone."
In a Locrian context, there is no perfect 5th! The diminished 5th doesn't resolve; it is not a passing tone.
Consequently, the Locrian sound is rarely used in a Pop or Blues context.
Off the top of my head; the intro to Enter Sandman by Metallica could be construed as Locrian as well as the song Sad But True. The bassline of Björks' Army of Me is Locrian. Locrian is fairly common in Metal and there are examples of it in Classical music. It's a cliché in horror films when something satanic or evil is suggested (the flying monkeys theme in the Wizard of Oz?).
But...chords found in basic Blues songs almost never have diminished 5ths in them. Jazz guys will play Dominant and Minor 7 chords with flatted-5ths in them all the time, but I'm talking basic, traditional, 3-chord, 12-bar Blues forms. If we go beyond that context, we are no longer "Quick & Dirty" and I will lose the folks at which this blog series is aimed.
Having said that, I'm going to have to give a Quick & Dirty lesson on Half-Diminished chords here, and the most common progression in which they're used so that those who are interested can contextualize the Locrian sound.
If you're interested, great! If not, that's fine too; as I said, this is the least used mode in popular music.
Another name for a Half-Diminished chord is Minor 7(b5). It has, as the term, "Minor 7 (b5)" dictates, a Minor 7 ("Minor 7" means the 7th is flatted in relation to a Major 7), a Minor 3rd and a Diminished (flatted) 5th. Here are two shapes, one 6th-string root and one 5th-string root:
A complete understanding of these chords can be found in Unit 4: 7th Chords.
Record or loop a Half-Diminished chord and practice improvising using your typical Minor Pentatonic patterns - don't forget to FLAT THE 5th!
You can find single-chord Half-Diminished backing tracks on YouTube, just do a search for them.
Remember the "around the Circle" instruction I gave above? Well, here is a Half-Diminished backing track that plays Half-Diminished chords around the Circle; 8 bars per key: All Half-Diminished Chords (Cycle of 4ths) - Slow Funk Backing Track.
Notice at the very end, the last bar is G7. That's because Half-Diminished/Locrian has an unresolved feeling. Without that resolution it would feel like continuing with no stopping point.
A Common Function of the Half-Diminished Chord
The most common function of the Half-Diminished chord is as the II chord in a II-V-I progression in a minor key.
We need to practice a 6th-string key (a key where I is on the 6th string) and a 5th-string key.
The 6th-string example will be the key of A:
II = Half-Diminished
V = Dominant flat-9
I = Minor 7
Note: If you don't understand these chords that's ok; for our purposes here just learn them by rote. For an explanation of the Half-Diminished and Minor 7 chord types, see the above link for Unit 4: 7th Chords. For the understanding of the altered dominant (the V chord), you can download a PDF, Quick & Dirty Altered Dominants, for free with no further commitment or obligation:
Notice in the above chords that the b5 of the B becomes the b9 of the E. That means that your B Minor Pentatonic with the b5 will work over the E7(b9) chord. Sweet! Double function! You would then switch to A Minor Pentatonic for the A-7 chord.
If switching scales in the middle of the progression is too much for you, play A Minor Pentatonic over the whole thing and add the Aeolian 6. See: The Aeolian/Dorian Distinction.
It just so happens that the Aeolian 6 of the A minor is the b5 of the B and the b9 of the E; very convenient!
For the 5th-string key we will do D minor:
II = Half-Diminished
V = Dominant 7
I = Minor 7
For the E-7(b5) we will play E Minor Pentatonic with the b5. That will also work over the A7 chord; the root, minor 3rd and the 4th of the E Minor Pentatonic are the 5th, the 7th and the root of the A7. Again, double function. Or...
Like the other example, a D Minor Pentatonic with the Aeolian 6 added will work over the whole thing. The Aeolian 6 of the D is the b5 of the E. So there ya go!
Flatting the 5th of the Minor Pentatonic scale does not constitute the complete Locrian Mode, but it gives a Locrian quality to the Minor Pentatonic.
If you were to flat the 5th of your Minor Pentatonic "stuff," an educated listener might say that you're using the Locrian mode, and they'd be right, but that's not the way we're thinking about it.
All we’re doing is flatting the 5th of the Minor Pentatonic scale, which gives the Pentatonic a Locrian quality.
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