Ab sus2/Cb
The Ab sus2 chord consists of the Ab (Perfect unison), Bb (Major second) and Eb (Perfect fifth) notes, with Cb as the bass note.

How to play the Ab sus2/Cb chord
- Play Cb as the lowest bass note in the left hand
- Find Ab (Root) on the piano keyboard
- Add Bb (Major second) — 2 semitones above Ab
- Add Eb (Perfect fifth) — 7 semitones above Ab
- Press all 4 notes simultaneously to sound the Ab sus2/Cb chord