semicord

Bbm9 Bb minor ninth chord

Notes
Bb Db F Ab C
Formula
1 b3 5 b7 9
Semitones
0 3 7 10 14 above the root
Also written
A#m9 (A# C# E# G# B#)
Other symbols
Bbmin9, Bb−9

Bb to Db is a minor third (3 semitones), Db to F is a major third (4 semitones), F to Ab is a minor third (3 semitones), Ab to C is a major third (4 semitones). A minor seventh (Bbm7) with a major ninth on top: C, 14 semitones above Bb. The fifth, F, is the note players drop first.

Bbm9 on the piano

C4D4E4F4G4A4B4C5D5E5F5G5A5B5C6D6E6F6G6A6B6C#4Eb4F#4Ab4Bb4Db5Eb5F#5Ab5Bb5C#6Eb6F#6Ab6Bb6C4BbC5DbFAbCC6

Root position from Bb4: Bb4, Db5, F5, Ab5, C6. Middle C is C4.

Bbm9 on the guitar

Standard tuning (E A D G B E). Strings run low E on the left to high e on the right, frets downwards; × is a muted string, ○ an open string, and each dot shows the note it sounds, with the root in blue-green. Every shape below has Bb as its lowest note.

6frBbBbFFAbAbDbDbFFCC
E-shape barre, root on the E string at fret 6
6 8 6 6 6 8 (low E to high e)
Sounds Bb2 F3 Ab3 Db4 F4 C5
11fr×BbBbDbDbAbAbCCFF
A-shape, root on the A string at fret 13
x 13 11 13 13 13 (low E to high e)
Sounds Bb3 Db4 Ab4 C5 F5

The E-shape and A-shape grips are movable: an E-shape chord's root is the note under your first finger on the low E string, an A-shape chord's root is the note on the A string. Slide the same grip up or down to play minor ninth chords on other roots.

Inversions of Bbm9

An inversion puts a note other than the root in the bass. The name is what semicord's chord finder calls those notes played bottom to top; a slash name like C/E means a C chord with E in the bass.

PositionNotes, bass firstNamedListen
Root positionBb Db F Ab CBbm9
1st inversionDb F Ab C BbBbm9/Db
2nd inversionF Ab C Bb DbBbm9/F
3rd inversionAb C Bb Db FBbm9/Ab
4th inversionC Bb Db F AbBbm7/C (also read as Bbm9/C)

Where Bbm9 fits

Bbm9 is ii9 in Ab major, vi9 in Db major, i9 in Bb minor. Its upper four notes Db F Ab C are Dbmaj7, the usual rootless voicing of Bbm9 over a Bb bass.