What notes are in a C augmented chord?

C augmented contains three notes: C (the root), E (the major third), and G♯ (the augmented fifth).

What does the + symbol mean?

The + sign is the standard chord-symbol notation for augmented. C+ means "C augmented triad." Some scores write it as "C(♯5)" or "Caug" instead.

Why are augmented chords symmetric?

Two stacked major thirds (4 + 4 semitones) total 8 semitones. Adding another major third reaches 12 — back to the root. So C+, E+, and G♯/A♭+ all contain the same three pitches in different inversions.

Where does C augmented appear in music?

In any harmonic-minor music in A minor (III+ chord), in chromatic-mediant Romantic harmony (C → C+ → F), and as a colour chord in jazz piano voicings. The Beatles' "Oh! Darling" opens with one.

C augmented chord — notes, intervals, and practice

C augmented — C, E, G♯ — stacks two major thirds on top of each other. The chord is symmetric: C+, E+, and A♭+ are all the same three pitches, just inverted. C+ most often appears as the III+ of A harmonic minor or as a chromatic-mediant colour in major-key writing.

Intervals

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

C→Emajor 3rd4 semitones
E→G#major 3rd4 semitones
C→G#augmented 5th8 semitones

On the keyboard

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

On the guitar

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

Common mistakes

The fifth is G♯, not G natural. Replacing G♯ with G makes a C major chord — a completely different harmonic colour. The augmented fifth is what creates the chord's "floating," unresolved sound. On piano, C+ is white-white-black; on guitar it's typically a small voicing on three strings, since the augmented fifth doesn't fit any standard barre shape.

In context

In A harmonic minor, C+ functions as the III+ chord: an augmented colour created by raising the leading tone (G♯ instead of G). The progression Am → C+ → F (i → III+ → VI) is a common Romantic-era turn. The Beatles' "Oh! Darling" uses an augmented chord at its opening for exactly this kind of suspended, anticipatory feel.

Drill it

The C 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.

Open the Chord Trainer →Or try today's Etudle puzzle

Frequently asked

What notes are in a C augmented chord?: C augmented contains three notes: C (the root), E (the major third), and G♯ (the augmented fifth).
What does the + symbol mean?: The + sign is the standard chord-symbol notation for augmented. C+ means "C augmented triad." Some scores write it as "C(♯5)" or "Caug" instead.
Why are augmented chords symmetric?: Two stacked major thirds (4 + 4 semitones) total 8 semitones. Adding another major third reaches 12 — back to the root. So C+, E+, and G♯/A♭+ all contain the same three pitches in different inversions.
Where does C augmented appear in music?: In any harmonic-minor music in A minor (III+ chord), in chromatic-mediant Romantic harmony (C → C+ → F), and as a colour chord in jazz piano voicings. The Beatles' "Oh! Darling" opens with one.