The Key of C — Lap Steel
The tonic, subdominant and dominant chords, and what this chair plays across them.
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 lap steel chair carries a held chord under the singer — the bar laid across the strings, slid into place and left to ring. Its strings are already tuned to a chord, CEGACE, so there is no shape to make — only a fret to lay the bar on, and the slide that gets it there in time for the change. Every diagram below is a straight bar or a short slant, and a quality this tuning cannot spell that way is marked instead of drawn.
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.