Short Answer
Overview
An augmented chord is a three‑note chord consisting of a root, a major third, and an augmented fifth (a raised perfect fifth). The intervallic structure can be expressed as 0–4–8 semitones from the root, creating a symmetrical shape that lacks a clear tonal center. Because the augmented fifth is a tritone away from the root, the chord generates considerable harmonic tension, often resolving to more stable chords such as major, minor, or dominant sevenths.
In practice, the augmented chord may appear in its basic triadic form (e.g., C°, C° includes C‑E‑G♯) or as part of extended harmonies, such as the augmented dominant seventh (C7°) where a minor seventh is added. Its ambiguous quality makes it a useful tool for composers and improvisers seeking to color a progression, modulate to distant keys, or create a sense of surprise.
History / Origin
The term “augmented chord” derives from the Latin *augere* meaning “to increase,” referring to the raised fifth. The concept emerged in the common‑practice period, particularly in the works of late‑Classical and early Romantic composers such as Beethoven and Chopin, who employed the chord to heighten drama. The systematic study of altered chords, including the augmented triad, was formalized in 19th‑century harmonic theory texts, and the chord later became a staple of jazz harmony in the 20th century.
How It’s Used
Augmented chords appear in a wide range of musical contexts. In classical music they often function as a passing chord or a pivot for modulation. In jazz, the augmented triad is frequently used as a substitution for dominant chords, especially in the “augmented dominant” (e.g., G7°) to lead to a resolution a half‑step up. Pop, rock, and film scores also employ the chord for dramatic effect, often notated with the symbol “+” (e.g., C+). Guitarists and pianists typically voice the chord in close position, while orchestral arrangements may spread the notes across different instrument sections.
Why It Matters
The augmented chord’s distinctive tension makes it valuable for creating emotional contrasts and facilitating smooth key changes. Its symmetrical structure allows for easy transposition, enabling improvisers to shift the chord up minor thirds while preserving its identity. Notable examples include the opening of “Maria” from *West Side Story* (which uses an augmented chord to convey yearning) and the bridge of The Beatles’ “A Day in the Life,” where an augmented chord heightens the song’s climax.
Common Misconceptions
An augmented chord is the same as a diminished chord.
An augmented chord contains a major third and an augmented fifth, whereas a diminished chord contains a minor third and a diminished fifth.
The “+” symbol always indicates a major seventh.
In chord symbols, “+” denotes an augmented fifth; a major seventh is indicated by “M7” or “Δ7.”
Augmented chords can only be used in jazz.
While common in jazz, augmented chords are employed across classical, pop, rock, film music, and many other genres for expressive purposes.
FAQ
How is an augmented chord notated in lead sheets?
It is typically written with a plus sign after the root (e.g., C+), or with the abbreviation “aug” (e.g., Caug).
Can an augmented chord be used as a substitution for a dominant chord?
Yes; the augmented dominant (e.g., G7+ or G7♯5) can replace a regular dominant to create a smoother voice leading to the tonic.
What is the difference between an augmented triad and an augmented seventh chord?
An augmented triad contains three notes (root, major third, augmented fifth), while an augmented seventh chord adds a seventh—usually a minor seventh—to the triad, forming a four‑note harmony.
Leave a Reply