Double C Tuning for Banjo

Double C runs G4, C3, G3, C4, D4, in playing order. The lowest-pitched string is C3 (130.81 Hz) and the highest is G4 (392.00 Hz), measured against A4 = 440 Hz. Those are the exact target frequencies the tuner on this page listens for.

2 of the 5 strings move: D3 down 2 semitone(s) to C3; B3 up 1 semitone(s) to C4. 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.

An old-time clawhammer tuning with two C strings an octave apart. Suits tunes in C and, capoed at the second fret, becomes Double D for the large body of old-time repertoire in D.

C3 is 130.81 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 banjo tuning.

Lowering the fourth string to C and raising the second to C gives two C strings an octave apart, with the high drone unchanged. Melodies in C gain a strong tonic anchor above and below, which is what old-time clawhammer playing leans on. Because it is a whole step below Double D, capoing at the second fret converts it directly, and since a large share of old-time repertoire sits in D that pairing is the practical reason the tuning survives. The drone string keeps its standard G, so it now sounds the fifth of the key rather than the root.