The B-sharp dominant seventh chord (abbreviated "B#7 chord") is a four-note chord consisting of the notes B♯, D, F, and A♯. The chord is formed by adding a minor seventh to a B-sharp major chord.
B-sharp dominant seventh chord
B-sharp major-minor seventh chord
B♯ D F A♯
1 3 5 ♭7
tetrad (four-note chord)