Ab major 13th chord
Abmaj13 chord for piano with keyboard diagram.
Explanation: The A flat major thirteenth is a six-note chord (the 11th, Db in the case of Abmaj13, is normally excluded). For practical reasons the chord is normally played with omitted notes and/or inverted. It is often abbreviated as Abmaj13 (not to be confused with Ab13).
Theory: The Ab major thirteenth chord is constructed by extending the major eleventh chord with a major thirteenth note.
Notes: Ab - C - Eb - G - Bb - F