Bb9 chord
The B-flat dominant ninth chord (abbreviated "Bb9 chord") is a five-note chord consisting of the notes B♭, D, F, A♭, and C. The chord is formed by adding a major ninth to a B-flat dominant seventh chord.
In practice, the fifth (F) is sometimes omitted from the Bb9 chord because it's not always possible to play all notes simultaneously.
Name
B-flat dominant ninth chord
Notes
B♭ D F A♭ C
Intervals
1 3 5 ♭7 9
Chord symbol
B♭9
Type
Pentad (five-note chord)