The augmented triad stacks two major thirds, producing 1-3-♯5. It is perfectly symmetric in equal temperament: any note can be heard as a root, which makes it a slippery pivot in modulation and a luminous color in jazz, classical, and pop harmony. Because every interval between chord tones is a major third, it sits naturally inside the whole-tone collection and pairs well with whole-tone scales and augmented arpeggios.
Construction
Formula: 1-3-♯5. In Caug, spell C-E-G♯. Enharmonic spellings (A♭ for G♯, etc.) are common for readability in keys.
Usage
Use as color on tonic or dominant function, as a passing chord between major triads by major-third root motion, and as a harmonic “lift” before resolving outward by semitone or whole step.
Examples
- Chopin and late Romantic augmented chains
- Jazz altered dominants where the augmented triad highlights ♯5 color
- Pop hooks that arpeggiate +5 for dreamy brightness
Play
Voice with open spacing to reduce beating, double sparingly, and decide which pitch you want listeners to hear as the root because symmetry is ambiguous.
Ear-training cues
Three pitches equally spaced by major thirds; a floating, bright, unstable center.
