A#7#9 — A# dominant seventh sharp nine chord
A dominant seventh chord with a raised ninth. It contains both the major third and the minor third in the octave above, which is what produces the chord's bite.
- 1 = A#
- 3 = C##
- 5 = E#
- b7 = G#
- #9 = B##
- Symbol
- A#7#9
- Root
- A#
- Quality
- Dominant seventh sharp nine
- Family
- altered
- Notes
- A# C## E# G# B##
- Degree formula
1 3 5 b7 #9- Semitones from the root
0 3 4 7 10- Distinct pitch classes
- 5
- Interval structure
- Stacked from the root: 4 semitones, 3 semitones, 3 semitones, 5 semitones
- Notation
- Written 7#9, and long associated in popular usage with the chord in the introduction to Purple Haze, hence its common nickname.
- Key
- A# · Bb major / G minor key signature
Formula
The chord tones in order from the root, with the interval each one forms above it.
| Degree | Note | Semitones | Interval from the root |
|---|---|---|---|
| 1 | A# | 0 | Perfect unison |
| 3 | C## | 4 | Major third |
| 5 | E# | 7 | Perfect fifth |
| b7 | G# | 10 | Minor seventh |
| #9 | B## | 3 | Minor third |
Inversions
An inversion is the same set of notes with a different one in the bass. The last column gives the distance of each note above the bass note, in semitones.
| Inversion | Bass note | Degree in the bass | Notes above the bass | Semitones above the bass |
|---|---|---|---|---|
| root position | A# | 1 | A# – C## – E# – G# – B## | 0 4 7 10 3 |
| first inversion | C## | 3 | C## – E# – G# – B## – A# | 0 3 6 11 8 |
| second inversion | E# | 5 | E# – G# – B## – A# – C## | 0 3 8 5 9 |
| third inversion | G# | b7 | G# – B## – A# – C## – E# | 0 5 2 6 9 |
| fourth inversion | B## | #9 | B## – A# – C## – E# – G# | 0 9 1 4 7 |
Playable voicings
These shapes were found by searching the fretboard of a standard-tuned guitar (E A D G B E) rather than copied from a chord book. The search allows every string to sound or to be muted, rejects any shape with a muted string between two sounding strings, rejects any shape whose fretted notes span more than four frets (a five-fret window), requires every chord tone to be present, and then sorts what remains with root-position shapes first and the most compact, lowest shapes next. The shapes shown are the first six of that ordering; other orderings are possible at the same frets.
| # | Shape (low string first) | Notes | Degrees | Bass | Span (frets) | Sounding strings |
|---|---|---|---|---|---|---|
| 1 | 6-5-6-6-6-6 | A# D G# C# F A# | 1 3 b7 #9 5 1 | A# | 1 | 6 |
| 2 | 6-5-6-6-6-4 | A# D G# C# F G# | 1 3 b7 #9 5 b7 | A# | 2 | 6 |
| 3 | 6-4-3-3-3-4 | A# C# F A# D G# | 1 #9 5 1 3 b7 | A# | 3 | 6 |
| 4 | 6-4-3-6-3-4 | A# C# F C# D G# | 1 #9 5 #9 3 b7 | A# | 3 | 6 |
| 5 | 6-5-3-6-3-4 | A# D F C# D G# | 1 3 5 #9 3 b7 | A# | 3 | 6 |
| 6 | 6-5-3-6-6-4 | A# D F C# F G# | 1 3 5 #9 5 b7 | A# | 3 | 6 |
Shape numbers run from the lowest string to the highest, so the left-hand number is the sixth string (low E) in standard tuning. Multiple shapes are listed because a chord can be voiced several ways, and because a lower position is not always the better sounding one.
Related chords and scales
- KeyEverything in A#
- ScaleA# diminished (half-whole)
- ChordA#7
- ChordA#7b5
Related