DADGAD Tuning for Guitar

DADGAD runs D2, A2, D3, G3, A3, 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; B3 down 2 semitone(s) to A3; 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.

A suspended fourth voicing that is deliberately neither major nor minor, which is what makes it sound modal rather than resolved. Strongly associated with Celtic and folk fingerstyle, where the ambiguity lets a melody imply the harmony instead of fighting it.

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.

Spelling D, A, D, G, A, D, this is a Dsus4 — root, fifth, root, fourth, fifth, root — with no third at all. The absence is the entire point: without a third the tuning refuses to commit to major or minor, so a melody note can imply either and the harmony follows rather than argues. That ambiguity maps directly onto modal folk repertoire, where tunes often sit between modes rather than in a key. Practically it also means a barre gives you a suspended chord rather than a triad, so the tuning rewards partial shapes and open-string drones over conventional grips.