Bb 13b9, 3rd inversion (G# in the bass)
Also written as Bb13b9/G#.
Notes, from the bass up
G# (bass)BGA#DE#
The same notes as Bb 13b9 (G#, B, G, A#, D and E#), rearranged so G# is the lowest note. Use it to move between chords with smaller jumps across the keyboard.