G7-9 (G7b9) altered chord
Altered G chord for piano presented by keyboard diagrams.
Explanation: The G7-9 alter the G9 by the change of one note. The chord name can also be written as G7b9 or G7(b9).
Theory: The G7-9 are identical with the G9 except that the major ninth is flattenedThe tone is one half step lower.
Notes: G - B - D - F - Ab