C7#9 — C 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 = C
- 3 = E
- 5 = G
- b7 = Bb
- #9 = D#
- Symbol
- C7#9
- Root
- C
- Quality
- Dominant seventh sharp nine
- Family
- altered
- Notes
- C E G Bb D#
- 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
- C · C major / A 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 | C | 0 | Perfect unison |
| 3 | E | 4 | Major third |
| 5 | G | 7 | Perfect fifth |
| b7 | Bb | 10 | Minor seventh |
| #9 | D# | 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 | C | 1 | C – E – G – Bb – D# | 0 4 7 10 3 |
| first inversion | E | 3 | E – G – Bb – D# – C | 0 3 6 11 8 |
| second inversion | G | 5 | G – Bb – D# – C – E | 0 3 8 5 9 |
| third inversion | Bb | b7 | Bb – D# – C – E – G | 0 5 2 6 9 |
| fourth inversion | D# | #9 | D# – C – E – G – Bb | 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 | 8-7-8-8-8-8 | C E A# D# G C | 1 3 b7 #9 5 1 | C | 1 | 6 |
| 2 | 8-7-8-8-8-6 | C E A# D# G A# | 1 3 b7 #9 5 b7 | C | 2 | 6 |
| 3 | 8-6-5-5-5-6 | C D# G C E A# | 1 #9 5 1 3 b7 | C | 3 | 6 |
| 4 | 8-6-5-8-5-6 | C D# G D# E A# | 1 #9 5 #9 3 b7 | C | 3 | 6 |
| 5 | 8-7-5-8-5-6 | C E G D# E A# | 1 3 5 #9 3 b7 | C | 3 | 6 |
| 6 | 8-7-5-8-8-6 | C E G D# G A# | 1 3 5 #9 5 b7 | C | 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 C
- ScaleC diminished (half-whole)
- ChordC7
- ChordC7b5
Related
- KeyKey of C
- ScaleC diminished (half-whole)
- ChordC7 — Dominant seventh
- ChordC7b5 — Dominant seventh flat five
- ChordC11 — Dominant eleventh
- ChordC13 — Dominant thirteenth
- ChordC6 — Sixth
- DegreesC — degree map