About the A nine suspended four chord
The A nine suspended four chord is a A ninth suspended fourth built from A, D, E, G, B. It sits outside the plain diatonic set, so it is borrowed to add color and tension.
Positions
(root position)
Notes and intervals
| 1 | A | Root |
| 2 | D | Perfect 4th |
| 3 | E | Perfect 5th |
| 4 | G | Minor 7th |
| 5 | B | Major 9th |
Shapes
Chromatic
Circle of Fifths
Other A chords
Simpler triads
Suspended
Sixths and sevenths
A six A minor six A minor flat six A seven A major seven A minor seven A minor seven flat five A diminished seven A minor major seven A major seven flat five A major seven sharp five A minor major seven flat five
Extensions
A nine A add nine A major nine A minor nine A eleven A thirteen A six nine A minor add nine A major eleven A major thirteen A minor eleven A minor thirteen A minor six nine A minor major nine A minor major eleven
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.
