A7#9: guitar chord voicings, inversions, scales and arpeggios

A7#9 (7#9) is an interactive GuitarArcanum page with chord formula, intervals, voicings, inversions, triads, pentatonic patterns, scales and arpeggios on the fretboard.

Chord formula

Interval formula: 1 3 5 b7 #9. A dominant 7th with a sharp 9th — the famous 'Hendrix chord.' Tough and brash, both major and minor at once to the ear.

Chord tones

The major 3rd clashes with the #9, which sounds like a minor third an octave up. That clash is the signature edge. The 3rd–b7 tritone keeps the dominant pull.

Sound character

Tough and brash, rock and jazz at once — the sound of 'Purple Haze' and funk riffs.

Harmonic function

An altered dominant. It can resolve, or sit as a static chord in funk and rock.

Typical progressions

  • E7#9 → C
  • Riff on a single E7#9
  • A7#9 – D7#9

Guitar voicing advice

The classic shape has the root on the 5th string: x7678x (E-shape). Keep the #9 on top and drop the 5th.

Compatible scales for A7#9

Other chord qualities on the A root

Compare this chord with other qualities sharing the same root.