The Key of C# — Banjo
The tonic, subdominant and dominant chords, and what this chair plays across them.
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. Most of the country repertoire in this key lives on three of those chords — the tonic, the subdominant and the dominant — plus the relative minor when a song wants one darker turn.
The banjo chair carries a three-finger roll behind the singer — a steady stream of picked notes through the chord, filling the eighths a two-feel leaves empty. The left hand holds the shape below and the right hand never strums it: thumb, index and middle pick through its strings one at a time, which is why a banjo chord reads as motion rather than as a block.
Learn the tonic-subdominant-dominant grammar in C# until your hand goes there without asking, then add the relative minor, and most of the repertoire in this key is already playable.