The A Augmented chord is a three-note chord made up of A, C♯, and E♯. It is built from a root, major third, and augmented fifth.
Construction
A Augmented = Root + Major 3rd + Minor 6th = A · C♯ · E♯
| Note | Interval | Degree |
|---|---|---|
| A | Root | 1 |
| C♯ | Major 3rd | 3 |
| E♯ | Minor 6th | ♯5 |
A Augmented Inversions
| Position | Notes |
|---|---|
| Root Position | A – C♯ – E♯ |
| 1st Inversion | C♯ – E♯ – A |
| 2nd Inversion | E♯ – A – C♯ |
Key Signature
A Augmented chord is built from symmetrical or ambiguous intervals, so it doesn’t belong to a single key and has no key signature of its own.
Same Notes, Other Names
The notes A – C♯ – E♯ aren’t exclusive to this chord. Depending on which note is the bass and how the chord functions, the same pitches also spell the following:
A Augmented — Frequently Asked Questions
What is the A Augmented chord on piano?
The A Augmented chord contains the notes A – C♯ – E♯. On piano, play these notes together to sound the chord.
What notes are in the A Augmented chord?
The A Augmented chord contains three notes: A (root), C# (major third), and E# (augmented fifth — one semitone higher than a perfect fifth). The augmented fifth is what gives this chord its tense, unresolved quality.
How does the A Augmented chord differ from A Major?
The only difference between A Augmented and A Major is the fifth: A Major has a perfect fifth, while A Augmented raises it by one semitone to an augmented fifth (E#). This single change transforms a stable, resolved chord into one full of tension and forward motion.
What is the symbol for the A Augmented chord?
The A Augmented chord is written as Aaug or A+. The "aug" or "+" symbol indicates the augmented fifth. In lead sheets and chord charts, both notations are common — Aaug appears in classical and jazz contexts while A+ is common in pop and rock.
How do I use the A Augmented chord in music?
Augmented chords create tension and a sense of motion. The most common uses are: (1) as a chromatic passing chord between the I and IV chords (e.g., A → Aaug → IV), (2) over a chromatic bass line moving upward, and (3) in jazz as a substitute for dominant chords. The augmented fifth wants to resolve up by one semitone.
What are the inversions of the A Augmented chord?
The A Augmented chord has a unique property: all three of its inversions are enharmonically equivalent. Because each note is separated by exactly 4 semitones (a major third), rotating the notes always produces the same interval structure. Aaug in root position, first inversion, and second inversion all sound the same quality.
What songs use augmented chords?
Augmented chords appear in Oh! Darling (Beatles), which uses Aaug as a chromatic passing chord, and in many jazz standards as chromatic dominant substitutes. Stevie Wonder and Elton John frequently use augmented chords for their characteristic tension-building quality.