The Key of C# — Lap Steel
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 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.