Bb addb9/Cb
The Bb addb9 chord consists of the Bb (Perfect unison), D (Major third), F (Perfect fifth) and Cb (Minor ninth) notes, with Cb as the bass note.

How to play the Bb addb9/Cb chord
- Play Cb as the lowest bass note in the left hand
- Find Bb (Root) on the piano keyboard
- Add D (Major third) — 4 semitones above Bb
- Add F (Perfect fifth) — 7 semitones above Bb
- Add Cb (Minor ninth) — 13 semitones above Bb
- Press all 5 notes simultaneously to sound the Bb addb9/Cb chord