The 7th mode. The most extreme. Five positions, all 12 keys, and the b5 tritone explained.
Locrian is the 7th mode of the major scale. If you play C major from B to B, you get B Locrian. Its formula is 1 b2 b3 4 b5 b6 b7. The defining feature is the flat fifth (b5), which creates a tritone from the root and makes the tonic chord diminished (Bdim) instead of minor.
B C# D E F# G A
Tonic chord: Bm (minor, stable)
Fifth: F# (perfect fifth)
Sound: dark but resolved
B C D E F G A
Tonic chord: Bdim (diminished, unstable)
Fifth: F (flat fifth, tritone from B)
Sound: extreme tension, unresolved
All positions shown for B Locrian (root at fret 7 on low E). The flat fifth (F) is highlighted in red in each position. The root (B) is highlighted in violet.
Start here. Root on low E at fret 7 (B). The b5 (F) appears at fret 8 on the A string -- one fret above the 5th you would expect. This one-fret difference is the tritone that makes Locrian feel so unstable. The b2 (C) also sits at fret 8 on the low E string.
Root on A string at fret 12 (or think D string fret 9). The b5 (F) appears on the D string at fret 10. This is a comfortable mid-neck position for Locrian runs. Notice the dense cluster of half-steps from the b2 through b3.
Root on low E at fret 12 (octave B). Same shape as Position 1 but one octave higher. The b5 (F) at fret 13 on the A string. Great for upper-register metal leads and horror film licks on the upper strings.
Root on G string at fret 4 (B). The b5 (F) is on the G string at fret 5 and also on the B string at fret 6. This position covers the lower end of the neck and is useful for linking back to Position 1.
Root on A string at fret 2 (B) and high e at fret 7 (B). The b5 (F) sits on the low E string at fret 1 and A string at fret 8. This position wraps around the open position and Position 1, completing the full-neck cycle.
All three scales share the b2 (flat second). The b5 in Locrian is the critical difference that makes it the most extreme mode.
| Feature | Natural Minor | Phrygian | Locrian |
|---|---|---|---|
| Formula | 1 2 b3 4 5 b6 b7 | 1 b2 b3 4 5 b6 b7 | 1 b2 b3 4 b5 b6 b7 |
| 2nd degree | Major 2nd (natural) | Flat 2nd (half-step above root) | Flat 2nd (half-step above root) |
| 5th degree | Perfect 5th (stable) | Perfect 5th (stable) | Flat 5th (tritone, unstable) |
| B key note | C# (fret 9 on A string) | C (fret 8 on A string) | F (fret 8 on A string) |
| Tonic chord | Bm (minor) | Bm (minor) | Bdim (diminished) |
| Sound | Dark, melancholic | Very dark, Spanish/Moorish | Extreme tension, chaotic |
| Genre home | Rock, metal, classical | Flamenco, metal, hip-hop | Jazz (m7b5), metal, film score |
| Root | Notes | b5 (Tritone) | Low E Root Fret | Best for |
|---|---|---|---|---|
| B | B - C - D - E - F - G - A | F | 7 | Jazz (Bm7b5 ii chord), metal |
| C | C - Db - Eb - F - Gb - Ab - Bb | Gb | 8 | Metal, horror film score |
| C# | C# - D - E - F# - G - A - B | G | 9 | Metal, avant-garde |
| D | D - Eb - F - G - Ab - Bb - C | Ab | 10 | Jazz, metal |
| Eb | Eb - E - Gb - Ab - A - B - Db | A | 11 | Avant-garde, film score |
| E | E - F - G - A - Bb - C - D | Bb | Open | Metal, dark ambient |
| F | F - Gb - Ab - Bb - B - Db - Eb | B | 1 | Jazz (half-diminished), film |
| F# | F# - G - A - B - C - D - E | C | 2 | Metal, progressive |
| G | G - Ab - Bb - C - Db - Eb - F | Db | 3 | Horror film score, metal |
| G# | G# - A - B - C# - D - E - F# | D | 4 | Avant-garde, metal |
| A | A - Bb - C - D - Eb - F - G | Eb | 5 | Metal, dark jazz |
| Bb | Bb - B - Db - Eb - E - Gb - Ab | E | 6 | Film score, avant-garde |
Locrian has a reputation as "unusable" because the tonic chord is diminished. But musicians use it in three concrete ways:
The most common use. In a minor ii-V-i (Bm7b5 - E7 - Am7), the Bm7b5 chord is built on the Locrian mode. Improvising over Bm7b5 with B Locrian is standard jazz practice. The b5 (F) is the defining chord tone (the flat 5 in m7b5).
Jazz standardBands like Slayer, Meshuggah, and Diablo Swing Orchestra use Locrian riffs for extreme dissonance. The b5 riff (root to b5 interval) is the tritone, historically called "diabolus in musica." Power chord riffs built on Locrian's i-bII give maximum darkness.
Extreme metalComposers use Locrian phrases for jump-scare moments and sustained dread. The diminished tonic creates unresolved tension that major and minor cannot. Bernard Herrmann's Psycho shower scene and John Carpenter's Halloween theme both draw on Locrian-adjacent tritone intervals.
Horror and suspenseIn jazz, the Super Locrian (also called the altered scale) is Locrian with an additional b4 (raising the fourth). It is used over dominant 7 altered chords (7b9, 7#9, 7b5, 7#5). If you play altered dominant jazz, you are already using a Locrian derivative.
Jazz altered dominant| Song / Example | Artist | Key | How Locrian Appears |
|---|---|---|---|
| Minor ii-V-i (Bm7b5 chord) | Jazz standard | B Locrian over Am | B Locrian over the half-diminished ii chord in any minor key jazz progression |
| Raining Blood | Slayer | E Locrian-adjacent | Tritone riff using the b5 interval for maximum aggression |
| Psycho (shower scene) | Bernard Herrmann | Tritone-based | String ostinato exploits the tritone and diminished harmonies central to Locrian |
| Oblivion | Astor Piazzolla | C# Locrian feel | Half-diminished chord as the starting tonal center creates an unresolved, yearning quality |
| Altered dominant phrases | John Coltrane, Miles Davis | Various | Super Locrian (altered scale) over 7b9/7#9 chords in bebop and modal jazz |
| Dimmu Borgir, Meshuggah riffs | Various extreme metal | Multiple keys | Locrian mode or Locrian-inflected riffs for tritone tension and chaos |
| Genre | How It Appears | Common Keys | Production Tip |
|---|---|---|---|
| Jazz | Half-diminished chord (m7b5), minor ii-V-i, altered dominant scale | B, E, A (natural minor ii chord keys) | Detect key with BeatKey, use B Locrian over the Bm7b5 chord in Am progressions |
| Metal / Extreme Metal | Tritone riffs (root to b5), full Locrian mode runs for chaos | E, B, F# (low tunings) | Palm mute root-to-b5 power chord riff, then open up to full Locrian run on lead |
| Horror Film Score | Sustained Locrian phrases, diminished tonic chords, tritone drone | C, G, D (orchestral friendly) | Layered strings sustaining a Locrian phrase with no resolution creates dread |
| Progressive Rock | Brief Locrian sections for maximum contrast against diatonic passages | B, F#, E | Use Locrian as a one- or two-bar tension phrase before resolving to Dorian or Aeolian |
| Avant-Garde / Experimental | Full Locrian tonal centers, exploiting the instability as the main sound | Any | Pedal tone on b5 (instead of root) creates an even more disorienting effect |
| Dark Hip-Hop / Trap | Sample-based Locrian chops, half-diminished chord loops as tonic vamp | B, E, F# | Chop a jazz sample with a Bm7b5 tonic chord, detect key with BeatKey, flip over 808 |
Play root (B) then jump directly to b5 (F). This tritone leap is the most recognized Locrian move. Used in metal riffs as a power chord (B5 to F5) and in jazz as the defining interval of the m7b5 chord.
Play 4 (E) then b5 (F) then resolve back to 4 (E). The b5 as a chromatic upper neighbor to the 4th is the gentlest way to use the Locrian tension without full commitment to the mode.
Unlike other modes, Locrian sounds best when you deliberately avoid settling on the root. The instability IS the point. End phrases on b3 (D), b7 (A), or b6 (G) for a floating, unresolved effect.
Phrygian and Locrian share the same b2 and b3. You can switch between them by raising (Phrygian, F#) or lowering (Locrian, F) just the fifth degree. This creates a dramatic shift in tension within a single riff.
Whenever you see a m7b5 chord (half-diminished), that chord is built on the 7th mode of a major scale. B Locrian over Bm7b5 in a minor ii-V-i progression is the most practical application. Detect the key first with BeatKey, then identify the half-diminished chord.
For experimental and avant-garde guitar, set an open-string drone on the b5 (F on the first fret of low E) instead of the root. Playing Locrian lines over an F drone creates an even more chaotic, tonally ambiguous effect than a B drone.
Upload any track, sample, or loop to BeatKey to detect its key instantly. Then use the result to select the correct Locrian root and position on this page.
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Locrian is the 7th mode of the major scale with the formula 1 b2 b3 4 b5 b6 b7. In B Locrian the notes are B C D E F G A. The flat fifth (F) makes the tonic chord diminished (Bdim instead of Bm). Locrian is used in jazz (half-diminished chords), metal (tritone riffs), and horror film scores.
In B Locrian Position 1 (root at fret 7 on low E), the flat fifth (F) is at fret 8 on the A string. This is one fret lower than the perfect fifth (F# at fret 9). That half-step drop creates the tritone interval that defines Locrian.
Three main uses: jazz (B Locrian over Bm7b5 in minor ii-V-i), metal (tritone riffs, extreme dissonance), and film score (horror and suspense cues). The Super Locrian (altered scale) is also used over altered dominant 7th chords in bebop jazz.
Both have a flat second (b2), but Locrian also has a flat fifth (b5) while Phrygian has a perfect fifth. In B, Phrygian has F# while Locrian has F. This flat fifth makes the Locrian tonic chord diminished (Bdim) instead of minor (Bm), giving Locrian extreme tension that Phrygian does not have.