Banjo B♭ chord (Open D)B♭ major on the 5-string banjo: 0 4 1 3, and 5 more shapes

Frets, string 4 to string 1: 0 4 1 3 (open position)

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

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

Found in: C mixolydian (♭VII), G dorian (♭III), C dorian (♭VII), G minor (♭III), D minor (♭VI), C minor (♭VII)

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

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