Gb9 chord

The G-flat dominant ninth chord (abbreviated Gb9 chord) is a five-note chord consisting of the notes G♭, B♭, D♭, F♭, and A♭. The chord is formed by adding a major ninth to the G-flat dominant seventh chord.

In practice, the fifth (D♭) is sometimes omitted from the Gb9 chord because it's not always possible to play all notes simultaneously.