C sus2
The C sus2 chord consists of the C (Perfect unison), D (Major second) and G (Perfect fifth) notes.

How to play the C sus2 chord
- Find C (Root) on the piano keyboard
- Add D (Major second) — 2 semitones above C
- Add G (Perfect fifth) — 7 semitones above C
- Press all 3 notes simultaneously to sound the C sus2 chord