Ab sixth/ninth chord
Ab6/9 chord for piano with keyboard diagram.
Explanation: The A flat sixth/ninth is a five note chord. Due to practical circumstances, however, the fifth (Eb) is often omitted and/or the chord is played inverted. The chord is abbreviated Ab6/9.
Theory: The Ab6/9 chord is constructed with a root, a major third, a perfect fifth, a major sixth and a major ninth.
Notes: Ab - C - Eb - F - Bb