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

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