Bb minor ninth chord
Bbm9 chord for piano with keyboard diagram.
Explanation: The Bb minor ninth is a five note chord. For practical reasons the chord is normally played with omitted notes and/or inverted. The chord is often abbreviated as Bbm9.
Theory: The Bbm9 chord is constructed with a root, a minor third, a perfect fifth, a minor seventh and a major ninth.
Notes: Bb - Db - F - Ab - C