What notes are in an A augmented chord?

A augmented contains three notes: A (the root), C♯ (the major third), and E♯ (the augmented fifth — same pitch as F).

Why is the fifth E♯ instead of F?

The augmented triad stacks thirds on consecutive odd-numbered letters: A-C-E. The fifth must sit on the E letter, which becomes E♯ when raised a half step from E natural.

Is A augmented the same as F augmented?

Enharmonically yes — same three pitches in different inversions. A+, C♯+, and F+ all share A, C♯ (= D♭), and F (= E♯) in pitch class.

How does A augmented resolve?

In F♯ minor, A+ resolves to D major (III+ → VI). In D major, A+ resolves to D with E♯ rising to F♯ — a stronger pull than the standard V → I cadence.

A augmented chord — notes, intervals, and practice

A augmented — A, C♯, E♯ — stacks two major thirds. A+ is enharmonically the same chord as C♯+ and F+ in inversion. The E♯ (= F natural) is the spelling tell that you're inside a sharp-key context. A+ functions as III+ of F♯ harmonic minor and as an altered V in D major.

Intervals

The A augmented chord stacks two thirds on the root. Each interval and its size in semitones:

A→C#major 3rd4 semitones
C#→E#major 3rd4 semitones
A→E#augmented 5th8 semitones

On the keyboard

Each note of the A augmented chord highlighted on a piano. Pitch class is what matters — any octave works.

On the guitar

One voicing of the A augmented chord on a six-string guitar fretboard.

Common mistakes

The fifth is E♯, enharmonic to F natural. In jazz chord-symbol practice, the chord is sometimes written A+ with F as the fifth letter — strictly incorrect by the seven-letter rule, but common on lead sheets. In notated classical music inside F♯-minor key areas, E♯ preserves spelling consistency.

In context

A+ functions as III+ of F♯ harmonic minor: F♯m → A+ → D (i → III+ → VI). In D major, A+ acts as an altered V chord with E♯ leading up to F♯ in the tonic chord. Schubert's late piano sonatas use augmented sonorities like this for chromatic mediant colour.

Drill it

The A augmented chord is one of 48 in the Chord Trainer. Open the full trainer to practice it alongside related chords with timing and best-time tracking.

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Frequently asked

What notes are in an A augmented chord?: A augmented contains three notes: A (the root), C♯ (the major third), and E♯ (the augmented fifth — same pitch as F).
Why is the fifth E♯ instead of F?: The augmented triad stacks thirds on consecutive odd-numbered letters: A-C-E. The fifth must sit on the E letter, which becomes E♯ when raised a half step from E natural.
Is A augmented the same as F augmented?: Enharmonically yes — same three pitches in different inversions. A+, C♯+, and F+ all share A, C♯ (= D♭), and F (= E♯) in pitch class.
How does A augmented resolve?: In F♯ minor, A+ resolves to D major (III+ → VI). In D major, A+ resolves to D with E♯ rising to F♯ — a stronger pull than the standard V → I cadence.