About the A sharp seven sharp nine chord
A sharp seven sharp nine sits outside the plain diatonic set, so it is borrowed to add color and tension. Think of it as an A♯ dominant seventh sharp nine chord.
Its notes are A♯, C♯♯, E♯, G♯, and B♯♯. The intervals are a major third, a perfect fifth, a minor seventh, and an augmented ninth.
Also called Hendrix chord and Purple Haze chord. B flat seven sharp nine spells the same notes enharmonically.
Positions
Notes and intervals
| 1 | A#A♯ | Root |
|---|---|---|
| 2 | C##C♯♯ | Major 3rd |
| 3 | E#E♯ | Perfect 5th |
| 4 | G#G♯ | Minor 7th |
| 5 | B##B♯♯ | Augmented 9th |
Shapes
Chromatic
Circle of Fifths
Other A sharp 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.