E maj11/C#
The E maj11 chord consists of the E (Perfect unison), G# (Major third), B (Perfect fifth), D# (Major seventh), F# (Major ninth) and A (Perfect eleventh) notes, with C# as the bass note.

How to play the E maj11/C# chord
- Play C# as the lowest bass note in the left hand
- Find E (Root) on the piano keyboard
- Add G# (Major third) — 4 semitones above E
- Add B (Perfect fifth) — 7 semitones above E
- Add D# (Major seventh) — 11 semitones above E
- Add F# (Major ninth) — 14 semitones above E
- Add A (Perfect eleventh) — 17 semitones above E
- Press all 7 notes simultaneously to sound the E maj11/C# chord