B#13 chord

The B-sharp dominant thirteenth chord (abbreviated B#13 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 the B-sharp dominant eleventh chord.

In practice, the fifth (F𝄪) and eleventh (E♯) are often omitted from the B#13 chord to avoid a very dissonant sound, and because it's not always possible to play all notes simultaneously.