Banjo Tunings, Derived

Retuning a banjo is pitch arithmetic, and arithmetic can be computed: which strings move, by how many semitones, what the open strings now spell, and which of your fretted shapes survive.

Retuning a banjo is arithmetic. Which strings move, by how many semitones, what the open set now spells, and which of your fretted shapes survive are all computable from the instrument's own pitches — so on this site they are computed. The only thing typed by hand on any of these pages is the list of target note names; every number below falls out of that.

The four tunings

Banjo tunings — every field derived from registry pitches
TuningStringsMovedOpen strings read as
Double CgCGCD2Csus2 / Gsus4
SawmillgDGCD1Csus2 / Gsus4
Open DaDF#AD3D major
Double DaDADE4Dsus2 / Asus4
Double CTwo Cs an octave apart — the old-time C tuning, derived string by string.gCGCD · 2 strings move SawmillOne string up a semitone, and the whole instrument turns modal.gDGCD · 1 string moves Open DThe open strings become a D major chord — standard tuning’s twin in D.aDF#AD · 3 strings move Double DDouble C transposed into D — the session tuning behind half the tunes in A.aDADE · 4 strings move

Two tunings, one set of letters

Notice that double C and sawmill sound the same three letters. They are not the same tuning: the letters are arranged differently across the strings, so the bass note differs and the tunes that sit well in each differ with it. That is the kind of thing a derived table shows and a written list hides.

Retune or capo?

A retune changes what the open strings are; a capo changes what key they are in. They are not substitutes. If you want the open-G system in a different key, the capo pages have the arithmetic — including the fifth-string spike, which is the part nobody else models.