B add11/D#
The B add11 chord consists of the B (Perfect unison), D# (Major third), F# (Perfect fifth) and E (Perfect eleventh) notes, with D# as the bass note.

How to play the B add11/D# chord
- Play D# as the lowest bass note in the left hand
- Find B (Root) on the piano keyboard
- Add D# (Major third) — 4 semitones above B
- Add F# (Perfect fifth) — 7 semitones above B
- Add E (Perfect eleventh) — 17 semitones above B
- Press all 5 notes simultaneously to sound the B add11/D# chord