Notes in C♯7♯9
The C♯7♯9 chord contains 5 notes: C♯, F, A♭, B, E
Intervals
| Interval | Semitones | Note | Function |
|---|---|---|---|
| R | 0 | C♯ | Root |
| 3 | 4 | F | Major 3rd |
| 5 | 7 | A♭ | Perfect 5th |
| ♭7 | 10 | B | Minor 7th |
| ♯9 | 3 | E | Augmented 9th |
About C♯ 7th Sharp 9 Chords
The 7♯9 chord — the 'Hendrix chord' — combines a dominant 7th with a sharp 9th (enharmonically, a minor 3rd). This creates a crunchy clash between the major 3rd and minor 3rd. Jimi Hendrix's 'Purple Haze' made this voicing iconic, but it appears throughout blues, funk, and jazz.
Compatible Scales & Modes
These scales contain all the notes of C♯7♯9 and can be used for soloing, improvising, and writing melodies over this chord.
Playing C# seventh sharp nine on Guitar
The C# seventh sharp nine chord, spelled C♯, F, A♭, B, E, occupies a specific harmonic role that depends on the musical context. In the key of Db major enharmonically, this chord can function as a primary harmony or as a passing color depending on where it appears in the progression. Understanding which scale degrees produce C#-rooted chords helps you predict chord progressions and improvise melodies that complement the harmony.
On guitar, C# seventh sharp nine voicings benefit from fourth-fret barre shapes that provide a bright, cutting tone. The physical shape of this chord on the fretboard determines its tonal character — the same notes arranged in different voicings produce noticeably different sounds due to string gauge, fret position, and overtone content. Experiment with playing C# seventh sharp nine in multiple positions to find the voicing that best fits the register and texture of the music you are working on.
The C#7#9 chord contains both a major third and a sharp nine (enharmonic minor third), creating the famous bluesy clash. This dissonance gives C#7#9 its gritty, aggressive character that defined psychedelic rock and continues to drive blues and funk guitar.
When practicing C# seventh sharp nine, use the compatible scales listed above to improvise melodies and riffs. Start by playing the chord, then explore the scale tones one at a time to hear how each note sounds against the harmony. This ear training exercise connects your theoretical knowledge of C#-rooted chords to practical musicianship skills that improve your playing across all genres and styles.