B 9th chord
B9 chord (also called Dominant 9th chord) for piano presented by keyboard diagrams.
Explanation: The B ninth is a five-note chord. Due to practical circumstances, however, the fifth (F#) is often omitted and/or the chord is played inverted. The chord is often abbreviated as B9.
Theory: The B ninth chord is constructed with a root, a major third, a perfect fifth, a minor seventh and a major ninth.
Notes: B - D# - F# - A - C#