A# maj13/G#
The A# maj13 chord consists of the A# (Perfect unison), D (Major third), F (Perfect fifth), A (Major seventh), C (Major ninth) and G (Major thirteenth) notes, with G# as the bass note.

How to play the A# maj13/G# chord
- Play G# as the lowest bass note in the left hand
- Find A# (Root) on the piano keyboard
- Add D (Major third) — 4 semitones above A#
- Add F (Perfect fifth) — 7 semitones above A#
- Add A (Major seventh) — 11 semitones above A#
- Add C (Major ninth) — 14 semitones above A#
- Add G (Major thirteenth) — 21 semitones above A#
- Press all 7 notes simultaneously to sound the A# maj13/G# chord