Fbm13 chord

The F-flat minor thirteenth chord (abbreviated Fbm13 chord) is a seven-note chord consisting of the notes F♭, A♭♭, C♭, E♭♭, G♭, B♭♭, and D♭. The chord is formed by adding a thirteenth to the F-flat minor eleventh chord.

In practice, the fifth (C♭) and eleventh (B♭♭) are often omitted from the Fbm13 chord to avoid a very dissonant sound, and because it's not always possible to play all notes simultaneously.