C Major 7 chord for piano with the piano diagram.
The Cmaj7 or C major 7 Chord is a tetrad, meaning it contains four notes. Also the shaded area in the piano diagram has four notes shaded is the chord.
C major 7 chord contains the root, major third(3rd), major fifth(5th) and major seventh(7th)
Left hand: 5-3-2-1 Right Hand: 1-2-4-5