Bb Minor Ninth chord (Bbm9) on the guitar fretboard

The Bb Minor Ninth chord (Bbm9) is made of Bb (the root), Db (minor third), F (perfect fifth, optional), Ab (minor seventh) and C (major ninth). The fretboard shows every one of them across the neck in standard tuning (E A D G B E), and plays them back so you can hear the chord.

The minor ninth is a minor seventh with a ninth stacked above, and the fifth is optional. Its notes repeat in several overlapping shapes on the neck. It sits between the minor seventh and the minor eleventh.