The Key of C# — Dobro

C# major harmonises to C# – D#m – Fm – F# – G# – A#m – C°; C# minor to C#m – D#° – E – F#m – G#m – A – B. 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.