What is the C7#9 Chord?
If you're learning the C7#9 chord, the fastest path is understanding the chord tones—not just memorizing one shape.
Notes and Arpeggios
The 7#9 is famously known as the "Hendrix chord" — a dominant 7th with a raised 9th that creates a gnarly clash between the major 3rd and what's essentially a minor 3rd up an octave. It's the sound of gritty, blues-rock tension at its most iconic. The complete chord tones are: C, E, G, Bb, D#. The complete formula is 1, 3, 5, b7, and #9.
How to Use It
You'll mostly hear altered dominants in jazz turnarounds and tense lead-in chords before a resolution. On bass, outline the harmony one note at a time. Start from the root and add the chord's actual degrees (3, 5, b7, and #9) as the arrangement allows. The chord-tone boxes locate notes; the ordered arpeggio gives a playable route with explicit position shifts.
Target the root on beat 1 and use degree 5 or the root octave to stabilize the groove. Use the highlights to spot where the same tone repeats across strings.