G Locrian — Venezuelan Cuatro

G Locrian is 7 notes to the octave (modes family), drawn here across the Venezuelan Cuatro's A-D-F#-B strings with every G marked, so home stays visible from anywhere in the pattern.

The most dissonant, unstable mode — the tonic chord is diminished (b5), making a true Locrian tonal center rare. Used for color and passing harmony.

Heard in: Metal riffs, jazz (half-diminished ø7 chords in ii°7 – V – i), horror and tension film scores.

Four strings inside a major sixth put a scale in a deliberately cramped place: the same pitch turns up on two strings constantly, and one open string sounds below the string next to it, so a run that looks like it climbs on paper can fall under the fingers. These maps light every root so the ear has an anchor.

Use it the way the music does — in short pieces, between strums. Very little of this repertoire asks a cuatrista for a long scalar run; what it asks for is three or four notes that land exactly where the strumming hand was about to brake.