What is a Thirteenth Chord?

A thirteenth chord is an extended chord that adds the thirteenth interval on top of a seventh chord. In theory, a full thirteenth chord can include up to seven different notes stacked in thirds: the root, third, fifth, seventh, ninth, eleventh, and thirteenth. The thirteenth is the same note as the sixth degree of the scale but played an octave higher. For example, a C13 chord may include the notes C, E, G, B♭, D, F, and A.

Because a full seven-note chord can be difficult to play on many instruments, musicians often leave out some notes when performing a thirteenth chord. Typically the root, third, seventh, and thirteenth are emphasized, while the fifth, ninth, or eleventh may be omitted. This helps maintain the character of the chord while keeping the voicing practical and clear.

Thirteenth chords are widely used in jazz, funk, soul, and modern pop music. They add a rich and colorful harmonic texture that expands beyond simple triads and seventh chords. Because of their lush sound and extended harmonic range, thirteenth chords are often used to create sophisticated chord progressions and smooth musical arrangements.