Cross Tuning for Mandolin

Cross Tuning (GDGD) runs G3, D4, G4, D5, in playing order. The lowest-pitched string is G3 (196.00 Hz) and the highest is D5 (587.33 Hz), measured against A4 = 440 Hz. Those are the exact target frequencies the tuner on this page listens for.

2 of the 4 strings move: A4 down 2 semitone(s) to G4; E5 down 2 semitone(s) to D5. Work through them in order, then go back and re-check the first string — retuning shifts the neck tension slightly, so the earlier strings drift as you go.

Borrowed from old-time fiddle cross tuning, giving open G and D drones across all four courses. The drones do the harmonic work so a melody can stay simple, which is exactly the old-time aesthetic.

G3 is 196.00 Hz at concert pitch (A4 = 440 Hz). That's the fundamental — the string also produces harmonics above it, which is why a tuner reading the wrong octave usually means it locked onto a harmonic rather than the fundamental. This is the lowest string in this mandolin tuning.

Lowering the A and E courses a whole step each gives G, D, G, D — the root and fifth doubled at two octaves, with no third anywhere. Like other drone tunings the absence of a third leaves modality open, and the doubled octaves mean nearly any melody note finds a sympathetic open string to ring against. Old-time players borrowed this directly from fiddle cross tuning for exactly that reason: the drones supply the harmony continuously, so the melody can stay stark and repetitive without sounding empty. Standard mandolin fingerings do not transfer, since the middle pair of courses is now a fourth apart rather than the fifth it was; the bottom and top pairs, untouched by the change, still sit a fifth apart.