G# m7/C
The G# m7 chord consists of the G# (Perfect unison), B (Minor third), D# (Perfect fifth) and F# (Minor seventh) notes, with C as the bass note.

How to play the G# m7/C chord
- Play C as the lowest bass note in the left hand
- Find G# (Root) on the piano keyboard
- Add B (Minor third) — 3 semitones above G#
- Add D# (Perfect fifth) — 7 semitones above G#
- Add F# (Minor seventh) — 10 semitones above G#
- Press all 5 notes simultaneously to sound the G# m7/C chord