A Locrian Mode for Melody Writers: Home Notes and Tension

A Locrian is a seven-note scale that starts on A and never quite lets you relax there. Its notes are A, Bb, C, D, Eb, F, G, and the note sitting five steps above the root, which is usually the solid, dependable one, has been pulled down a half step to Eb. That one change makes the whole scale feel like a room with a tilted floor. For a melody writer that is a challenge, but it is also a gift: few scales give you this much built-in tension to play with.

Seven letters, seven notes

Start with the spelling, because it explains a lot. In any standard scale, each letter name from A to G appears exactly once. That is why you see Bb instead of A#: we already have an A, so the second note has to use the letter B. The same rule gives us Eb rather than D#, because D is already taken as the fourth note. If those flats look odd for a scale rooted on a plain A, don't worry. They are not mistakes or alternatives. They are simply the only spelling that keeps one note per letter, and once you see the pattern it reads cleanly on paper.

The formula describes each note by its distance from A: 1, b2, b3, 4, b5, b6, b7. An interval is just the distance between two notes, and a "b" in front of a number means that note is a half step lower than it would be in a major scale. A half step is the smallest step in Western music, like moving from one piano key to the very next one, black or white. A whole step is two half steps.

Walk up from A using the step pattern H - W - W - H - W - W - W and you land on every note in turn: A up a half step to Bb, a whole step to C, a whole step to D, a half step to Eb, then whole steps to F, G and back to A. On a piano, play it slowly and notice how the very first move is that tiny half step. Most scales open with a confident whole step. This one starts by barely moving.

Borrowed from Bb major

These are exactly the same notes as Bb major (Bb, C, D, Eb, F, G, A). The difference is where you treat as home. Play Bb major from A to A and you have A Locrian. That means it shares Bb major's key signature of 2 flats, Bb and Eb, and it also shares that signature with G minor, Bb major's relative minor. Sheet music for an A Locrian piece will usually carry those two flats.

A useful comparison: A natural minor is A, B, C, D, E, F, G. Locrian takes that and lowers two notes, the 2nd to Bb and the 5th to Eb. Sing both versions back to back and you'll hear how much darker and more unsettled the Locrian sounds.

Which notes feel like home, and which want to leave

Here is the melody writer's map. A is home, but a shaky one. C, the minor 3rd, is a comfortable place to pause and gives the tune its minor colour. D is steady too, and it often feels oddly more grounded than the root.

Then come the restless notes. Bb sits a half step above A and leans heavily down onto it, a sighing, slightly menacing pull. Eb is the character note. It lies a tritone (three whole steps, the famously tense interval) above A, and it wants to slide somewhere: down to D or up to F. Land on Eb and hold it, and the listener will feel the floor tilt. That's the Locrian sound in a single note.

The trick is that Eb also undermines A. Because the 5th above the root is diminished rather than perfect, A never gets the sturdy support a normal root has. So your ear is constantly tempted to hear D or Bb as the real home. Good Locrian melodies keep returning to A, often through that Bb-to-A half step, to remind everyone where the centre is.

The chords underneath

Stacking every other note of the scale gives these chords:

• i°: Adim (A-C-Eb) / Am7b5
• bII: Bb (Bb-D-F) / Bbmaj7
• biii: Cm (C-Eb-G) / Cm7
• iv: Dm (D-F-A) / Dm7
• bV: Eb (Eb-G-Bb) / Ebmaj7
• bVI: F (F-A-C) / F7
• bvii: Gm (G-Bb-D) / Gm7

The home chord is diminished, which is why the scale never settles. To keep A as the centre, stay close to it. Try Am7b5 – Bbmaj7 – Am7b5 – Gm7, looping. The Bb chord slips a half step up and falls back, and the Gm7 adds a gentle shadow before the return. If you let Bb or Gm linger too long, the music starts sounding like Bb major or G minor instead.

Jazz players meet this sound constantly: Am7b5 is the ii chord in G minor, and A Locrian is a standard choice of notes over it. Heavier rock and metal styles also lean on Locrian riffs for that uneasy, dissonant edge.

Writing a short Locrian tune

Keep phrases short, begin and end on A, and let Eb appear in the middle as the moment of tension. A simple shape: A, Bb, C, Bb, A, then a second phrase C, D, Eb, D, C, Bb, A. Sing it or play it over a held Am7b5. The first phrase sets up home; the second reaches for Eb and tumbles back down through the Bb half step. Rhythm helps too: put A on strong beats and Eb on weaker ones, so the tension passes rather than settles.

For guitarists

Your A roots are at the 5th and 17th frets of the low E string, and on the A string open, at the 12th fret and at the 24th. The open A string is a gift here: let it ring as a drone while you play the melody above it on higher strings, and the Bb and Eb will clash against it in exactly the right way. Starting from the 5th fret of the low E string gives you a compact shape for riffs, with the Bb just one fret above the root.

Try this: hum a low A and hold it, then sing the tune above, pausing on the Eb for a full two beats before stepping down. Notice how much you want to move off it, and write a second ending that resolves to D instead of A to hear how fragile the home really is.

For the bigger picture, read The Locrian Mode.