The standard grips this chord is usually shown with.
Bbm9 is Bb, Db, F, Ab and C — Bbm7 with the ninth stacked above it.
It sounds warm, and considerably richer than an m7. The standard voicing for a ii chord once the plain one has been played enough.

| Bb | Db | F | Ab | C |
|---|---|---|---|---|
| 1 | ♭3 | 5 | ♭7 | 9 |
Pre-dominant or minor tonic — an m7’s job with more colour.
Also written Bbmin9, Bb-9 or Bb minor 9. The same chord either way; which spelling you meet depends on who wrote the chart.
Bbm9 in 9th in bass puts C in the bass instead of Bb, the 9th of the chord. The notes are the same; what changes is what the bass line does, which is most of why you would reach for it — it lets the lowest voice move by step where the root would have jumped.
One of Bbm9’s 7 common shapes does this: x33324.
Start with xx3524 — no barre and down at the nut. None of the shapes for Bbm9 uses an open string, so every one of them is movable; the lowest sits at the 2nd fret. 4 of the 7 need a barre. Together they cover the neck from the 2nd fret to the 13th.
| Frets | Where | Bass | Top | Hand |
|---|---|---|---|---|
| x33324 | 2nd fret | C, 9th in the bass | Ab | barred |
| xx3524 | 2nd fret | F, 2nd inversion | Ab | all fretted |
| 64x564 | 4th fret | Bb, root position | Ab | all fretted |
| x46566 | 4th fret | Db, 1st inversion | Bb | barred |
| 686668 | 6th fret | Bb, root position | C | barred |
| 9-11-10-10-11-9 | 9th fret | Db, 1st inversion | Db | all fretted |
| x-13-11-13-13-x | 11th fret | Bb, root position | C | barred |
The same notes rebuilt from scratch give 3 shell, 10 drop 2, 7 drop 3 and 14 rootless voicings, each on its own page.
Tensions. A shell of Bbm9, root, third and seventh, leaves a string free, and the tones that belong over it are the 11 (Eb) and the 13 (G).
How you get to it. The turn that lands on Bbm9 is Cm7♭5 to F7♭9: the ii and the V of Bb minor, which is where a minor tonic is usually arrived at rather than simply begun on.
In which keys. Every note of Bbm9 belongs to C# major (the vi, the submediant), F minor (the iv, the subdominant), Ab major (the ii, the supertonic) and Bb minor (the i, the tonic).
Every note of Bbm9 is in Bb dorian and Bb natural minor.
Change one note of Bbm9 and you have Bbm69 (the flat seventh becomes a sixth), Bbm7 (drop the ninth), Bbm11 (add the fourth), BbmMaj9 (the flat seventh becomes a major seventh), Bbmadd9 (drop the flat seventh) or Bb9 (the minor third becomes a major third).
Bbm9 is a minor chord — root, minor third, fifth. Minor chords on every root.
On Bbm9’s sound and use this page follows Mark Levine, The Jazz Theory Book (Sher Music, 1995). The shapes and the derived voicings come from different places, and both are explained in where the chords and the theory come from.
Shows each chord the way this style would voice it, and marks which of its alternatives belong to the idiom.