About the B flat thirteen suspended four chord
The B flat thirteen suspended four chord is a B flat thirteenth suspended fourth built from B flat, E flat, F, A flat, C, G. It sits outside the plain diatonic set, so it is borrowed to add color and tension.
It is also written A sharp thirteen suspended four , which spells the same notes enharmonically.
Positions
(root position)
Notes and intervals
| 1 | B flat | Root |
| 2 | E flat | Perfect 4th |
| 3 | F | Perfect 5th |
| 4 | A flat | Minor 7th |
| 5 | C | Major 9th |
| 6 | G | Major 13th |
Shapes
Chromatic
Circle of Fifths
Other B flat 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.
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.
