B aug/C#
The B aug chord consists of the B (Perfect unison), D# (Major third) and G (Minor sixth) notes, with C# as the bass note.

How to play the B aug/C# chord
- Play C# as the lowest bass note in the left hand
- Find B (Root) on the piano keyboard
- Add D# (Major third) — 4 semitones above B
- Add G (Minor sixth) — 8 semitones above B
- Press all 4 notes simultaneously to sound the B aug/C# chord