Bb7(#9) chord
The B-flat dominant seventh sharp ninth chord (abbreviated "Bb7(#9) chord") is a five-note chord consisting of the notes B♭, D, F, A♭, and C. The chord is formed by adding an augmented ninth to a B-flat dominant seventh chord.
In practice, the fifth (F) is often omitted from the Bb7(#9) chord because it's not always possible to play all notes simultaneously.
Name
B-flat dominant seventh sharp ninth chord
Synonym
B-flat dominant sharp ninth chord
Notes
B♭ D F A♭ C
Intervals
1 3 5 ♭7 ♯9
Chord symbol
B♭7(#9)
Alternative symbol
B♭7#9
Type
Pentad (five-note chord)