Bb13 chord

The B-flat dominant thirteenth chord (abbreviated "Bb13 chord") is a seven-note chord consisting of the notes B♭, D, F, A♭, C, E♭, and G. The chord is formed by adding a thirteenth to a B-flat dominant eleventh chord.

In practice, the fifth (F) and eleventh (E♭) are often omitted from the Bb13 chord to avoid a very dissonant sound, and because it's not always possible to play all notes simultaneously.