Fb9 chord

The F-flat dominant ninth chord (abbreviated Fb9 chord) is a five-note chord consisting of the notes F♭, A♭, C♭, E♭♭, and G♭. The chord is formed by adding a major ninth to the F-flat dominant seventh chord.

In practice, the fifth (C♭) is sometimes omitted from the Fb9 chord because it's not always possible to play all notes simultaneously.