The Key of C — Dobro

C major harmonises to C – Dm – Em – F – G – Am – B°; C minor to Cm – D° – D# – Fm – Gm – G# – A#. A caller does not say any of that. They say the key and then hold up fingers, and the whole circle is expected to translate.

C is not one of the four keys a bluegrass circle usually calls, so when it comes up it is because a singer needed it — and somebody in the band is capoing to make their shapes fit.

Learn 1–4–5 in C until your hand goes there without asking, then 1–6m–4–5 and the 2–5 that walks into a tag, and most of the repertoire is already playable in this key.