C Major Ninth chord (Cmaj9) on the guitar fretboard

The C Major Ninth chord (Cmaj9) is made of C (the root), E (major third), G (perfect fifth, optional), B (major seventh) and D (major ninth). The fretboard shows every one of them across the neck in standard tuning (E A D G B E), and plays them back so you can hear the chord.

The major ninth is a major seventh chord with a ninth added on top. The fifth is optional, which lets the shape thin out on the neck. It sits between the major seventh and the major eleventh in the family of tall major chords.