Guitar Chord Ab7#9: Structure, Notes and Theory

Ab7#9 — a chord built on the note “Ab” with an energetic sound and a strong pull toward resolution. A classic element of jazz and blues progressions, adding drive and a sense of phrase completion. The chord includes alterations: #9 — a sharp dominant color, best placed in the top voice for clarity.

Formula and Structure of the Ab7#9 Chord

Interval formula from the root note: 1 — 3 — 5 — b7 — #9. The chord consists of the following notes:

• Ab — unison and the main tonal anchor.
• C — major third with a bright major quality and clear stability above the tonic.
• Eb — perfect fifth, stabilizing the triad and adding tonal grounding.
• Gb — minor seventh with dominant pull toward the tonic.
• B — sharp ninth with a bright spark of dominant color, especially beautiful in the top voice.

Together, these notes form the harmonic foundation of the Ab7#9 chord, defining its sound and role in the musical context.

Alternative Names for the Ab7#9 Chord

There are no alternative names for this chord.

Using the Ab7#9 Chord

Build a stable frame from the 3 and b7, keeping them in fixed positions. Add colors (#9, b9, #11, b13) sparingly to preserve clarity. Classic usage is II–V–I, but it can also work in bebop runs. It’s useful to omit the fifth temporarily to make room for color tones.

Conclusion

Ab7#9 is an expressive and versatile chord. Learn several fingerings, experiment with different positions and voice spacing, then try weaving it into your own playing — this will help you quickly find your unique tone.