C Augmented Triad

Chord Tones: C Augmented Triad

Symbol: aug, + — Formula: 1-3-♯5

Chord Notation

Roman numeral (e.g. I, IV, V) and Nashville Number notation are key-dependent. See Keys pages for chord function within specific keys.

Inversions

Harmonic Function

The C augmented chord commonly functions as the tonic (I) in C major/minor. Its harmonic role varies by key — in major keys it provides stable harmonic grounding.

The augmented triad consists of two stacked major thirds, creating a symmetrical, ambiguous chord. Its raised fifth gives it a tense, unresolved quality that pulls toward resolution. The C Augmented Triad specifically contains 3 notes: C, E, G♯ (formula: 1-3-♯5). On piano, C-rooted chords sit entirely on white keys in their basic triad form, making them the first chords most students learn. Pop, folk, and singer-songwriter music heavily use C-rooted chords because open-position guitar voicings and piano shapes are immediately accessible.

Common Progressions

The C Augmented Triad frequently appears in these progression patterns (shown in Roman numeral notation relative to key):

• Iaug-IV
• Vaug-I

Songs Featuring the Augmented Triad

Well-known songs where the C Augmented Triad — or this chord type — plays a prominent role:

• Oh! You Pretty Things – David Bowie
• All Blues – Miles Davis
• Michelle – The Beatles

Tuning Frequencies Across Temperaments

Frequencies shown at A=440 Hz. View full temperament data for any note.

Scales Containing the C Augmented Triad

These scales include the C Augmented Triad as a diatonic or characteristic chord: