C add13
The C add13 chord consists of the C (Perfect unison), E (Major third), G (Perfect fifth) and A (Major thirteenth) notes.

How to play the C add13 chord
- Find C (Root) on the piano keyboard
- Add E (Major third) — 4 semitones above C
- Add G (Perfect fifth) — 7 semitones above C
- Add A (Major thirteenth) — 21 semitones above C
- Press all 4 notes simultaneously to sound the C add13 chord