Chord Detail
A Augmented Triad
Aaug is a A augmented triad — formed by raising the fifth of a major triad by one semitone. This creates two stacked major thirds and a restless, ambiguous sound that sits between major and something entirely unresolved.
The augmented triad is built from two stacked major thirds: 4 semitones above the root, and another 4 semitones above that (8 semitones total = an augmented fifth). Aaug uses A, C#, F. The augmented fifth (F) creates tension — it is one semitone above a perfect fifth, making the chord feel unstable and yearning. The augmented triad is symmetrical: every inversion produces the same set of pitch classes. This is why it sounds rootless and floating. In harmonic practice, augmented chords typically appear as passing chords or tension chords before resolution. In jazz, they often substitute for the V chord for a more colorful approach.
Formula: 1 – 3 – ♯5
1Root0 semitones3Major Third4 semitones♯5Augmented Fifth8 semitonesMysterious, ambiguous, tense, and exotic. Neither clearly major nor minor — it floats in harmonic ambiguity.
Augmented chords replace the perfect fifth with an augmented fifth, creating a dreamy, harmonically ambiguous sound. Because every interval is equidistant, they have no clear tonal center — making them perfect for unexpected transitions and harmonic color.
🌀 Other mysterious sounds to explore
The augmented triad is symmetrical — each interval is 4 semitones. This means inverting it produces an enharmonically equivalent chord. Use sparingly and let it resolve. On piano, raise just the fifth of a major chord by one semitone. Works well in slow harmonic rhythm as a surprise color chord.
I – I+ – IV (Chromatic inner voice)V+ – I (Augmented dominant approach)III+ – vi (Minor movement)I – III+ – VI (Ascending chromatic)Function
Color / Passing
Ambiguous / Floating
Symmetrical and tonally unanchored — used for chromatic color and altered dominant function.
Aaug is tonally ambiguous — its symmetrical structure allows it to resolve as an altered dominant toward C♯ major, F major, or A major. Composers use it as a chromatic passing chord or as an intensified V+ that heightens the pull toward resolution.
Scales that naturally contain the Aaug chord:
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