Irish bouzouki B♭ chord (ADAD)B♭ major: 1 3 1 0, and 3 more shapes

Frets, low course to high: 1 3 1 0 (open position)

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

Found in: G dorian (♭III), D minor (♭VI), G minor (♭III), F major (IV), B♭ major (I), E♭ major (V)

Open courses that ring: D is a note of B♭, so it can drone under it.

Tuning ADAD: A D A D, low to high.

The link can’t set the tuning: the app starts on the Irish bouzouki in GDAD. Choose ADAD once in its Settings and it remembers.

More B♭ shapes

D minor (♭VI, a main chord): Dm – C – B♭ – C
F major (IV, a main chord): F – B♭ – F – C (a plain backing for many reels and jigs)
C mixolydian (♭VII, a main chord): C – B♭ – C
F mixolydian (IV, a main chord): F – B♭ – F – E♭ (reels in D or A mix)
C dorian (♭VII, a main chord): Cm – B♭ – Cm
F dorian (IV, a main chord): Fm – E♭ – B♭ – Fm (the major IV is the dorian colour)