About the B seven flat nine chord
The B seven flat nine chord is a B dominant seventh flat nine built from B, D sharp, F sharp, A, C. It sits outside the plain diatonic set, so it is borrowed to add color and tension.
Inversions
(root position)
Notes and intervals
| 1 | B | Root |
| 2 | D sharp | Major 3rd |
| 3 | F sharp | Perfect 5th |
| 4 | A | Minor 7th |
| 5 | C | Minor 9th |
Shapes
Chromatic
Circle of Fifths
Other B chords
Simpler triads
Suspended
Sixths and sevenths
Extensions
Altered
Functional relationships
These chords are where this one most naturally comes from and resolves to inside a key.
Relative minor
The relative minor uses the same notes and key signature, so it works as a calmer, darker home base.
Parallel minor
The parallel minor keeps the same root note but lowers the third, giving the same key a darker, sadder sound.
Dominant
The dominant is a fifth above the root, and it builds tension that pulls strongly back to this chord.
Subdominant
The subdominant is a fourth above the root (a fifth below), and it usually leads on to the dominant or back home.
Tritone substitution
The tritone substitution is a dominant chord a tritone away that shares the same tension, so it can stand in for this chord and resolve the same way.
