B9 B dominant ninth chord
- Notes
- B D# F# A C#
- Formula
- 1 3 5 b7 9
- Semitones
- 0 4 7 10 14 above the root
- Other symbols
- Bdom9
B to D# is a major third (4 semitones), D# to F# is a minor third (3 semitones), F# to A is a minor third (3 semitones), A to C# is a major third (4 semitones). A dominant seventh (B7) with the ninth, C#, on top. Guitarists usually leave out the fifth, F#; the chord still reads as B9 while the third D# and seventh A are there.
B9 on the piano
Root position from B4: B4, D#5, F#5, A5, C#6. Middle C is C4.
B9 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 B as its lowest note.
x 2 1 2 2 2 (low E to high e)
Sounds B2 D#3 A3 C#4 F#4
7 9 7 8 7 9 (low E to high e)
Sounds B2 F#3 A3 D#4 F#4 C#5
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 dominant ninth chords on other roots.
Inversions of B9
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.
| Position | Notes, bass first | Named | Listen |
|---|---|---|---|
| Root position | B D# F# A C# | B9 | |
| 1st inversion | D# F# A C# B | B9/D# | |
| 2nd inversion | F# A C# B D# | B9/F# | |
| 3rd inversion | A C# B D# F# | B9/A | |
| 4th inversion | C# B D# F# A | B7/C# (also read as B9/C#) |
Where B9 fits
B9 is V9 in E major. It resolves like B7. In funk and blues it is also played as I9, IV9 and V9 of a twelve-bar blues, with no pull to resolve at all. Without the root, its upper four notes D# F# A C# are D#m7b5, which is why pianists who leave the root to the bass player grab that shape.