A add11
The A add11 chord consists of the A (Perfect unison), C# (Major third), E (Perfect fifth) and D (Perfect eleventh) notes.

How to play the A add11 chord
- Find A (Root) on the piano keyboard
- Add C# (Major third) — 4 semitones above A
- Add E (Perfect fifth) — 7 semitones above A
- Add D (Perfect eleventh) — 17 semitones above A
- Press all 4 notes simultaneously to sound the A add11 chord