Chords
Ab Dominant sharp ninth
Ab · C · Eb · Gb · B
The Hendrix chord — a dominant seventh with a raised ninth, major and minor thirds colliding on purpose.
Ab Dominant sharp ninth
Ab · C · Eb · Gb · B
Voicings on the piano
| Voicing | Notes | Play it on your instrument |
|---|---|---|
| Closed, root position | Ab3 · C4 · Eb4 · Gb4 · B4 | |
| Open (drop 2) | Gb3 · Ab3 · C4 · Eb4 · B4 | |
| Shell | Ab3 · C4 · Gb4 | |
| Rootless | C4 · Gb4 · B4 |
Tap a key or a fret to hear it.
Anatomy
Ab Dominant sharp ninth (Ab7#9) contains the notes Ab · C · Eb · Gb · B, each with a role measured as an interval from the root.
Read on: how triads are built · seventh chords · extensions
Inversions
An inversion of Ab Dominant sharp ninth puts a chord tone other than Ab in the bass; the name after the slash is that bass note.
Where it lives
The keys and the scales Ab Dominant sharp ninth belongs to.
In which keys
Ab Dominant sharp ninth is not diatonic to any major or minor key: at least one of its notes lies outside every one of them.
Scales that contain it
Ab Dominant sharp ninth fits inside these scales, each built on Ab.
- Ab Hungarian MajorAb · B · C · D · Eb · F · Gb
- Ab Bebop MinorAb · Bb · Cb · C · Db · Eb · F · Gb
- Ab Kafi RagaAb · Cb · C · Db · Eb · F · Gb · G
- Ab Messiaen's Mode #3Ab · Bb · Cb · C · D · Eb · Fb · Gb · G
Understanding the Ab Dominant sharp ninth chord
Names and symbols
Ab7#9 is the chord symbol for Ab Dominant sharp ninth.
How it is built
On Ab it is Ab · C · Eb · Gb · B, stacking 1P · 3M · 5P · 7m · 9A. The ♯9 is enharmonically the minor third, so the chord contains both thirds at once.
How it is used
That collision is the sound of the blues written into a single chord — the blue third rubbing against the major third of the dominant. Purple Haze made it famous; funk, hard bop and soul have used it ever since.
Learn this properly
Chapter 17: Theory in StylesCommon questions
- What notes are in Ab7#9?
- Ab7#9 contains Ab · C · Eb · Gb · B. Name any set of notes with the chord identifier.
- Why is it called the Hendrix chord?
- Purple Haze opens on E7♯9, and the association stuck. The chord predates him, but he made it a signature.
- Why does a ♯9 work over a major third?
- The ♯9 is enharmonically the minor third — the blue note. Hearing both at once is exactly what blues-derived harmony does.
- What notes are in the Ab Dominant sharp ninth chord?
- The Ab Dominant sharp ninth chord contains the notes Ab · C · Eb · Gb · B: the root Ab with the intervals 1P, 3M, 5P, 7m, 9A stacked above it. Play them together for the chord or one after another for an arpeggio. The lowest note is normally Ab, but any chord tone can take the bass in an inversion.
- What intervals make up the Ab Dominant sharp ninth chord?
- Measured from Ab, the Ab Dominant sharp ninth chord stacks the intervals 1P, 3M, 5P, 7m, 9A. The quality of the third and of the seventh, if there is one, is what gives the chord its character; the rest of the notes colour it. Every interval in the formula links to its own page, with its sound.