What is the F#7#9 Chord?
Here's a fretboard view of the F#7#9 chord so you can see where each chord tone lives across the neck. This chord is enharmonically equivalent to Gb7#9.
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: F#, A#, C#, E, A. 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.
Connect this chord to the next harmony using nearby chord tones. Shift the hand when the line needs it rather than stretching beyond a comfortable position. Use the highlights to spot where the same tone repeats across strings.