The B-flat dominant seventh suspended fourth chord (abbreviated "Bb7sus4 chord") is a four-note chord consisting of the notes B♭, E♭, F, and A♭. The chord is formed by adding a minor seventh to a B-flat suspended fourth chord.
B-flat dominant seventh suspended fourth chord
B♭ E♭ F A♭
1 4 5 ♭7
tetrad (four-note chord)