B Locrian Mode: The All-White-Key Mode That Never Settles
Sit at a piano, put your thumb on any B, and walk straight up the white keys to the next B. You've just played B Locrian. There are no black keys and no sharps or flats to think about, just seven plain white notes: B, C, D, E, F, G, A. That simplicity is a little misleading, because this is the most restless, off-balance sound you can make from those familiar keys. Starting on B changes everything about how the same notes behave.
Seven White Keys, Starting From the "Wrong" Place
Those white keys are exactly the notes of C major. B Locrian borrows C major's whole collection and simply treats B as home instead of C. Musicians call C major the parent scale, and the two share a key signature, which is the set of sharps or flats written at the start of a piece of sheet music to tell you which notes to alter. Here there are none. The page looks just like C major, and that's correct.
Because the parent is C major, B Locrian is also related to the other modes of that key: A minor (the relative minor of C), D Dorian, E Phrygian, G Mixolydian and so on. All of them are the same white keys with a different note given the job of home base.
Each note gets its own letter name: B, then C, D, E, F, G, A, with no letter skipped and none used twice. That's why nothing needs a sharp or flat. Every note lands naturally on its letter.
Where the Half Steps Hide
Look closely at a keyboard and you'll notice two spots where white keys sit side by side with no black key between them: B to C, and E to F. Those are half steps, the smallest step in Western music, like moving from one key to the very next one. Everywhere else among the white keys, a black key sits in the gap, so the distance is a whole step, two half steps.
Read B Locrian from the bottom and the pattern comes out like this:
- B to C: half step
- C to D: whole step
- D to E: whole step
- E to F: half step
- F to G: whole step
- G to A: whole step
- A to B: whole step
That's H - W - W - H - W - W - W. The very first move is a half step, so the second note crowds right up against the root. Measured from B, that C is a minor 2nd (the b2). The rest of the formula follows: 1, b2, b3, 4, b5, b6, b7. Almost every note sits on the low side of what a major scale would give you.
The F That Changes Everything
The note that defines this mode is F, the flat 5th, also called a diminished 5th. Play B and F together on the piano. That's a tritone, an interval of three whole steps that splits the octave right down the middle. It sounds tense and unresolved, a bit like a question with no answer.
Nearly every other scale has a perfect 5th above its root, the strong, stable interval that makes a home note feel like home. B Locrian doesn't. Its fifth is bent down by a half step, and that's why the mode floats instead of landing. Sing B, then F, then back to B, and you'll hear the strangeness straight away.
The Chords Built From These Notes
Stack every other note of the scale and you get these triads (three-note chords) and seventh chords (four-note chords):
- i°: Bdim (B-D-F) / Bm7b5
- bII: C (C-E-G) / Cmaj7
- biii: Dm (D-F-A) / Dm7
- iv: Em (E-G-B) / Em7
- bV: F (F-A-C) / Fmaj7
- bVI: G (G-B-D) / G7
- bvii: Am (A-C-E) / Am7
The home chord, Bdim, is a diminished triad, with that tritone from B to F built right into it. Its seventh-chord version, Bm7b5, is what jazz players call a half-diminished chord, and the Locrian mode is the standard scale choice for improvising over one.
Try this progression on piano: Bdim – C – Am – Bdim. Notice how badly that C chord wants to become home. The challenge of Locrian is keeping B in charge, so return to it often, hold it, and repeat it in the bass. A two-chord vamp of Bm7b5 to Cmaj7 shows the same tug of war very clearly.
How a Melody Moves Here
Melodies in B Locrian tend to circle the root nervously. The C right above B pulls downward hard, so lines often sink from C back to B with a dark, sighing effect. The F gives you a sour, unsettled color whenever you lean on it.
For songwriters and singers, short repeated phrases work best: start on B, touch C or F, and fall back to B. Long rising melodies tend to drift toward C and lose the Locrian feel. That's why the sound turns up mostly in fleeting moments, in jazz lines over half-diminished chords and in the heaviest corners of metal, where riffs lean on the b2 and b5 for menace.
A Quick Note for Guitarists
Find your B root on the low E string at fret 7 (or 19), or on the A string at fret 2 (or 14). From the 7th-fret B, play the scale up through one position and keep coming back to that low B. On the A string at fret 2, try a slow riff alternating B with C and F, and you'll hear the same tension the piano gives you.
About Cb Locrian
You might see Cb Locrian mentioned somewhere. It sounds exactly the same as B Locrian, but it's spelled with a pile of flats, 12 of them. Nobody writes it that way in practice, so B Locrian, with its clean white keys, is the spelling you'll actually use.
Something to Try
Hold a low B with your left hand on the piano. With your right, play only B, C and F in any order you like, slowly, for one minute. Then let your right hand land on C and listen to how much it wants to stay there. Go back to B, and you'll feel the mode's restlessness in your hands.
For the bigger picture, read The Locrian Mode.