Chord · Ab Dominant 7♭5
A♭7♭5 Chord
A♭7♭5 is Ab, C, D and Gb — tritone-substitution flavor; whole-tone sound.
A♭7♭5 on every instrument
The same 4 notes, 2 sets of hands. Open a diagram for alternate shapes, audio and the mistakes to avoid.
What A♭7♭5 is made of
Ab Dominant 7♭5 (Ab dominant 7♭5) is built from the notes Ab, C, D, Gb, with the interval pattern 1, 3, b5, b7. A common dominant 7♭5 chord across many styles.
Stack 1, 3, b5 and b7 on a root of A♭ and you get Ab, C, D and Gb. That interval recipe is what makes the chord a seventh flat five chord — move the same shape to another root and the character travels with it, which is why C7♭5 sounds like a transposed A♭7♭5.
Dominant 7♭5: Tritone-substitution flavor; whole-tone sound.
Spelling: the notes above are written the way a score would write them, not simplified to the nearest piano key. That is why this chord is spelled with A♭ rather than its enharmonic equivalent.
Keys that contain A♭7♭5
No major or natural-minor key contains all 4 of these notes — this one gets borrowed.
Chords like this one sit outside the diatonic set — they arrive as secondary dominants, borrowed chords or passing harmony. Browse every key to see which progressions pull it in.
Other chords on A♭
Same root, different colour.
The same seventh flat five shape, moved
The identical interval recipe, built on other roots.
Questions people ask about Ab7b5
- What notes are in the Ab7b5 chord?
- Ab7b5 is made of Ab, C, D and Gb — the 1, 3, b5 and b7 degrees of a seventh flat five chord built on Ab.
- What keys use the Ab7b5 chord?
- No major or natural-minor key contains all 4 notes of Ab7b5. Chords like this arrive as borrowed harmony — secondary dominants, harmonic-minor colour, or chromatic passing chords — rather than as one of a key's native chords.
- How do you play Ab7b5 on guitar and piano?
- This page shows Ab7b5 on guitar and piano — 4 voicings in total. Each diagram links to the full instrument page with alternate shapes, audio and common mistakes.
- Is Ab7b5 the same as G#7b5?
- Yes. Ab7b5 and G#7b5 are enharmonic — identical pitches written two different ways. Which spelling you use depends on the key you are in; Ab7b5 is the spelling this site treats as canonical.
Learn the theory behind it
Why A♭7♭5 behaves the way it does — the guides that explain the chord instead of just spelling it.