D m11/B
The D m11 chord consists of the D (Perfect unison), F (Minor third), A (Perfect fifth), C (Minor seventh), E (Major ninth) and G (Perfect eleventh) notes, with B as the bass note.

How to play the D m11/B chord
- Play B as the lowest bass note in the left hand
- Find D (Root) on the piano keyboard
- Add F (Minor third) — 3 semitones above D
- Add A (Perfect fifth) — 7 semitones above D
- Add C (Minor seventh) — 10 semitones above D
- Add E (Major ninth) — 14 semitones above D
- Add G (Perfect eleventh) — 17 semitones above D
- Press all 7 notes simultaneously to sound the D m11/B chord