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

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