The F-flat dominant seventh chord (abbreviated "Fb7 chord") is a four-note chord consisting of the notes F♭, A♭, C♭, and E♭♭. The chord is formed by adding a minor seventh to a F-flat major chord.
F-flat dominant seventh chord
F-flat major-minor seventh chord
F♭ A♭ C♭ E♭♭
1 3 5 ♭7
Tetrad (four-note chord)