semicord

Bbmaj9 Bb major ninth chord

Notes
Bb D F A C
Formula
1 3 5 7 9
Semitones
0 4 7 11 14 above the root
Also written
A#maj9 (A# C## E# G## B#)
Other symbols
BbM9, BbΔ9

Bb to D is a major third (4 semitones), D to F is a minor third (3 semitones), F to A is a major third (4 semitones), A to C is a minor third (3 semitones). A major seventh (Bbmaj7) with the ninth, C, on top. The fifth, F, is often left out on guitar.

Bbmaj9 on the piano

C4D4E4F4G4A4B4C5D5E5F5G5A5B5C6D6E6F6G6A6B6C#4Eb4F#4Ab4Bb4C#5Eb5F#5Ab5Bb5C#6Eb6F#6Ab6Bb6C4BbC5DFACC6

Root position from Bb4: Bb4, D5, F5, A5, C6. Middle C is C4.

Bbmaj9 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.

×BbBbDAACC×
A-shape, root on the A string at fret 1
x 1 0 2 1 x (low E to high e)
Sounds Bb2 D3 A3 C4, fifth left out
5frBbBbDDAACCFF×
E-shape, root on the E string at fret 6
6 5 7 5 6 x (low E to high e)
Sounds Bb2 D3 A3 C4 F4

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 major ninth chords on other roots.

Inversions of Bbmaj9

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 D F A CBbmaj9
1st inversionD F A C BbBbmaj9/D
2nd inversionF A C Bb DBbmaj9/F
3rd inversionA C Bb D FBbmaj9/A
4th inversionC Bb D F ABbmaj9/C

Where Bbmaj9 fits

Bbmaj9 is Imaj9 in Bb major, IVmaj9 in F major. Its upper four notes D F A C are Dm7: play that chord over a Bb bass and you have Bbmaj9.