Banjo Cm chord (Open D)C minor on the 5-string banjo: 1 1 3 1, and 3 more shapes

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

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

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

Found in: C dorian (i), G minor (iv), C minor (i), B♭ major (ii), E♭ major (vi), A♭ major (iii)

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

With a capo: on the 5th fret it’s 0 1 1 0 (frets counted from the capo), an open Gm shape. Spike the 5th string at the 10th fret to keep it in tune with the capo.

Open D tuning: f♯DF♯AD, the short 5th string first, then strings 4 to 1.