E Minor 9b5, 2nd inversion (Bb in the bass)
Also written as Em9b5/Bb.
Notes, from the bass up
Bb (bass)DF#EG
The same notes as E Minor 9b5 (Bb, D, F#, E and G), rearranged so Bb is the lowest note. Use it to move between chords with smaller jumps across the keyboard.