G# Locrian Mode: The Questions Students Actually Ask
A jazz pianist reaches the turnaround of a minor blues and drops a dark, slightly sour chord before the band lands back home. That chord is half-diminished, and the scale players reach for over it is Locrian. You also hear this sound in heavy metal riffs that refuse to resolve and in film cues where something is clearly wrong. G# Locrian is that same uneasy colour, sitting on G#. Here are the questions students tend to ask me about it, with straight answers.
What notes are in G# Locrian, and why are they spelled like that?
The notes are G#, A, B, C#, D, E, F#. Seven notes, and each letter from A to G appears exactly once. That's the rule for spelling any seven-note scale: every letter gets one turn. It keeps the scale readable on paper and makes each note's job clear.
So the second note is A, not G##. The fifth note is D, not C##. Both would sound identical, but using each letter once gives you clean, honest names. Measured from G#, the formula is 1, b2, b3, 4, b5, b6, b7. That means a root, a minor 2nd, a minor 3rd, a perfect 4th, a diminished 5th, a minor 6th and a minor 7th. An interval is simply the distance between two notes, and those labels describe how far each note sits above G#.
You might see this scale written as Ab Locrian. It sounds exactly the same, but spelled from Ab it needs 9 flats, which is awkward to read. Don't let that worry you. G# is the friendlier spelling, and it's the one musicians will expect.
Where does it come from, and what key signature does it use?
Locrian is a mode, which means a scale made by taking a major scale and starting it from a different note. G# Locrian uses the exact notes of A major (A, B, C#, D, E, F#, G#), just starting and resolving on G#, the seventh note of A major.
That gives it A major's key signature: 3 sharps, F#, C# and G#. A key signature is the group of sharps or flats written at the start of a piece so you don't have to mark them on every note. Because the notes are shared, G# Locrian is closely related to A major and its relative minor, F# minor, as well as the other modes from the same family, like B Dorian and E Mixolydian.
The step pattern shows how it fits together. A half step is the smallest move in Western music, one piano key to the very next. A whole step is two half steps. Locrian runs H - W - W - H - W - W - W. From G#: a half step to A, whole to B, whole to C#, half to D, then whole steps to E, F# and back up to G#. Play it on piano and you'll find it's almost all white keys, with black keys only on G#, C# and F#.
Which note makes it sound so uneasy?
The D. It's the flat 5th, or diminished 5th, of G#. Almost every scale you know has a perfect 5th, the steady interval that makes a chord feel grounded. Locrian swaps it for a note a half step lower, and the floor drops out.
Sing G# and then D above it. That interval is the tritone, three whole steps wide, and it sounds tense and suspended. Now sing G# up to D# (a perfect 5th) and hear how much calmer it feels. That one half step is the whole personality of the mode.
What chords can I play with it?
Build a chord on each note of the scale using only scale notes and you get:
- i°: G#dim (G#-B-D) / G#m7b5
- bII: A (A-C#-E) / Amaj7
- biii: Bm (B-D-F#) / Bm7
- iv: C#m (C#-E-G#) / C#m7
- bV: D (D-F#-A) / Dmaj7
- bVI: E (E-G#-B) / E7
- bvii: F#m (F#-A-C#) / F#m7
Notice the home chord is diminished, a chord built from two stacked minor 3rds. It never sounds fully at rest, which is exactly the point. The danger is that A major, sitting right above it, sounds so comfortable your ear wants to move in and call it home.
A progression to try: G#m7b5 - A - G#m7b5 - Bm, a bar each, looping. Keep returning to G#m7b5 and let the A chord be a brief, bright visitor. The half step slide from G# to A in the bass is the hook. Avoid lingering on E or C#m, which tend to drag things toward A major.
How does a melody behave in G# Locrian?
Restlessly. A Locrian melody doesn't settle so much as circle. The A just above the root pulls down hard onto G#, giving phrases a sighing, falling quality. The D keeps poking at the tension.
Songwriters and producers get the most out of it by repeating the root a lot, in the bass or as a held drone, so the ear has an anchor. Start and end phrases on G#, lean on D for colour, and treat A as the note that resolves down. Short, rhythmic figures work better than long lyrical lines, which is one reason the sound turns up in riff-based heavy music.
I play guitar. Where do I start?
Find G# on the low E string at fret 4 (or 16 an octave up), or on the A string at fret 11 (or 23). Fret 4 is the comfortable home base: play the scale up from there across the strings, then try the A string root at fret 11 to hear it in a higher register. Palm-mute an open-feeling chug on G# and drop in the A and D for that tight, dark riff sound.
Here's your task for today: hold a low G# (piano left hand, a drone track, or a bass note), and improvise for two minutes using only G#, A and D. Let every phrase fall from A to G#, and see how long you can stay unsettled before your ear begs for something else.
For the bigger picture, read The Locrian Mode.