The Key of B — Dobro
What the caller means when they hold up fingers, and what this chair plays.
B major harmonises to B – C#m – D#m – E – F# – G#m – A#°; B minor to Bm – C#° – D – Em – F#m – 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.
B is one of the four keys a bluegrass jam habitually calls, and this chair gets there by the bar laid straight across fret 4. That is the difference between reading a chord chart and sitting in.
Learn 1–4–5 in B 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.