Chord · A Augmented
Aaug Chord
Aaug is A, C# and E# — unsettled, dreamlike; symmetrical.
Aaug on every instrument
The same 3 notes, 6 sets of hands. Open a diagram for alternate shapes, audio and the mistakes to avoid.
What Aaug is made of
Aaug (A augmented) is built from the notes A, C#, E#, with the interval pattern 1, 3, #5.
Stack 1, 3 and #5 on a root of A and you get A, C# and E#. That interval recipe is what makes the chord an augmented chord — move the same shape to another root and the character travels with it, which is why Caug sounds like a transposed Aaug.
Augmented: Unsettled, dreamlike; symmetrical.
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 C♯ rather than its enharmonic equivalent.
Keys that contain Aaug
No major or natural-minor key contains all 3 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 augmented shape, moved
The identical interval recipe, built on other roots.
Questions people ask about Aaug
- What notes are in the Aaug chord?
- Aaug is made of A, C# and E# — the 1, 3 and #5 degrees of an augmented chord built on A.
- What keys use the Aaug chord?
- No major or natural-minor key contains all 3 notes of Aaug. 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 Aaug on guitar and piano?
- This page shows Aaug on guitar, piano, ukulele, bass, mandolin and banjo — 9 voicings in total. Each diagram links to the full instrument page with alternate shapes, audio and common mistakes.
Learn the theory behind it
Why Aaug behaves the way it does — the guides that explain the chord instead of just spelling it.