The Key of C — Mandolin

C major harmonises to C – Dm – Em – F – G – Am – B°; C minor to Cm – D° – D# – Fm – Gm – G# – A#. 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 mandolin chair carries the chop on the backbeat — a closed, muted chord landing where a snare would, and a chop is a chord with the ring taken out of it — closed shapes only, damped the instant they sound, landing where a snare would.

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.