Banjo B♭m7 chord (Open D)B♭ minor seventh on the 5-string banjo: 3 4 4 6, and 2 more shapes

Frets, string 4 to string 1: 3 4 4 6 (from the 3rd fret)

1. String 4 (D): 3rd fret, index finger, F
2. String 3 (F♯): 4th fret, middle finger, B♭
3. String 2 (A): 4th fret, ring finger, D♭
4. String 1 (D): 6th fret, little finger, A♭
5. String 5, the short f♯: open, F♯, not in the chord

Sounds: F B♭ D♭ A♭  ·  B♭m7 is B♭, D♭, F, A♭ (1 · ♭3 · 5 · ♭7)

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

With a capo: on the 3rd fret it’s 0 1 1 3 (frets counted from the capo), an open Gm7 shape. Spike the 5th string at the 8th 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.