Open G Tuning for Guitar

Open G runs D2, G2, D3, G3, B3, D4, in playing order. The lowest-pitched string is D2 (73.42 Hz) and the highest is D4 (293.66 Hz), measured against A4 = 440 Hz. Those are the exact target frequencies the tuner on this page listens for.

3 of the 6 strings move: E2 down 2 semitone(s) to D2; A2 down 2 semitone(s) to G2; E4 down 2 semitone(s) to D4. 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.

Three strings drop a whole step and the rest stay put, giving an open G major chord. Strongly associated with Delta blues and with rock players who remove the sixth string entirely and treat it as a five-string open tuning.

D2 is 73.42 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 guitar tuning.

Open strings spell D, G, D, G, B, D — a G major triad with the root doubled and the fifth appearing three times. Only the sixth, fifth and first strings move, all down a whole step, making it one of the least disruptive open tunings to reach. Its quirk is that the lowest string is the fifth rather than the root, so the open chord is technically a second inversion; players who want a root-position voicing remove the sixth string entirely, which is how the five-string open G setup associated with slide-heavy rock came about.