Bb Dominant 7#11 (Bb7#11)
Also written as A# Dominant 7#11 (A# and Bb are the same key).
Notes in Bb Dominant 7#11
Inversions
Same notes as Bb Dominant 7#11, with a different chord tone as the lowest note. Useful for smoother movement between chords instead of jumping around the keyboard.
Root position
A# in the bass
1st inversion
D in the bass
2nd inversion
E# in the bass
3rd inversion
G# in the bass
4th inversion
E in the bass
Open voicings
A close-position chord like Bb Dominant 7#11 can sound cluttered in the middle of the keyboard. Jazz players open it up by dropping one note down an octave, spreading the same notes wider without changing the chord.
Drop 2
G# on the bottom
Drop 3
E# on the bottom
Press A#, D, E#, G# and E together on the keyboard and you're playing Bb Dominant 7#11.
A dominant seventh with a sharpened eleventh on top. Jazz players call this the Lydian dominant sound: the raised eleventh takes the edge off a plain dominant chord and leaves something brighter and more floating. It turns up over dominant chords that resolve down a half step, and over static vamps that never resolve at all.