Added tone chord
(重定向自Added sixth)
![Suspended chord (sus2) and added tone chord (add9) both with D (ninth=second), distinguished by the absence or presence of the third (E♭).[1]](/uploads/202412/17/Sus_chord5944.png)

![Two added chords with mixed thirds, thirds separated by octave. Play chord on left [6] Play chord on right](/uploads/202412/17/Added_or_mixed_third_chord5944.png)

An added tone chord is a non-tertian chord composed of a tertian triad and an extra "added" note. The added note is not a seventh (three thirds from the chord root), but typically a non-tertian note, which cannot be defined by a sequence of thirds from the root, such as the added sixth ( Play ) or fourth. This includes chords with an added thirteenth (a tertian note, six thirds from the root) and farther "extensions", but that do not include the intervening tertian notes as in an extended chord. The concept of added tones is further convenient in that all notes may be related to familiar chords.