Banjo C♯ chord (Double C)C♯ major on the 5-string banjo: 1 1 1 3, and 3 more shapes

Frets, string 4 to string 1: 1 1 1 3 (first position)

1. String 4 (C): 1st fret, index finger (barre), C♯
2. String 3 (G): 1st fret, index finger (barre), G♯
3. String 2 (C): 1st fret, index finger (barre), C♯
4. String 1 (D): 3rd fret, ring finger, E♯
5. String 5, the short g: open, G, not in the chord

Sounds: C♯ G♯ C♯ E♯  ·  C♯ is C♯, E♯, G♯ (1 · 3 · 5)

Found in: F♯ major (V), D♭ major (I), A♭ major (IV), E♭ mixolydian (♭VII), D♭ mixolydian (I), A♭ mixolydian (IV)

The 5th string: the short g rubs against the G♯ in this shape, a semitone away: some players let it ring, some skip it.

With a capo: on the 1st fret it’s 0 0 0 2 (frets counted from the capo), an open C shape. Spike the 5th string at the 6th fret to keep it in tune with the capo.

Double C tuning: gCGCD, the short 5th string first, then strings 4 to 1.