A Locrian Mode

What is the A Locrian Mode?

Locrian is the seventh and darkest mode of the major scale, with both a ♭2 and a ♭5 that produce a diminished tonic triad — making it inherently unstable and restless. It's rarely used as a tonal center in traditional music, but metal and progressive players lean into that instability for intense, dissonant passages. Here's how the A Locrian Mode lays out on the fretboard.

Notes and Positions

The seventh mode - the darkest diatonic mode with a flat 5th. On bass, this scale becomes a toolkit for strong roots, passing tones, and melodic fills that still support the groove. Think in root-on-E and root-on-A boxes, then adapt the same notes for 5-string bass when the low B string gives you another root below the pattern. In the key of A, the notes are: A, Bb, C, D, Eb, F, G.

How to Use It

You'll often hear it in Metal, Jazz, and Modal. A good way to internalize the sound is to sing the root, then sing a few scale degrees before you play them.

Build two-bar bass lines that return to the root before experimenting with wider melodic movement. Use the interactive fretboard above to spot repeats of the same note on different strings and frets.