Banjo A chord (Double C)A major on the 5-string banjo: 1 2 1 2, and 3 more shapes

Frets, string 4 to string 1: 1 2 1 2 (first position)

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

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

Found in: A major (I), D major (V), A mixolydian (I), B mixolydian (♭VII), B dorian (♭VII), B minor (♭VII)

The 5th string: the short g adds the ♭7 over A, a colour rather than a clash.

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