G# 13/A
The G# 13 chord consists of the G# (Perfect unison), C (Major third), D# (Perfect fifth), F# (Minor seventh), A# (Major ninth) and F (Major thirteenth) notes, with A as the bass note.

How to play the G# 13/A chord
- Play A as the lowest bass note in the left hand
- Find G# (Root) on the piano keyboard
- Add C (Major third) — 4 semitones above G#
- Add D# (Perfect fifth) — 7 semitones above G#
- Add F# (Minor seventh) — 10 semitones above G#
- Add A# (Major ninth) — 14 semitones above G#
- Add F (Major thirteenth) — 21 semitones above G#
- Press all 7 notes simultaneously to sound the G# 13/A chord