Ab7-9 (Ab7b9) altered chord
Altered Ab chord for piano presented by keyboard diagrams.
Explanation: The Ab7-9 alter the Ab9 by the change of one note. The chord name can also be written as Ab7b9 or Ab7(b9).
Theory: The Ab7-9 are identical with the Ab9 except that the major ninth is flattenedThe tone is one half step lower.
Notes: Ab - C - Eb - Gb - A