Augmented Triad - Harmonic Considerations

Harmonic Considerations

Whereas a major triad, such as C-E-G, contains a major third (C-E) then a minor third (E-G), with the interval of the fifth (C-G) being "perfect", the augmented triad sharpens that fifth (to an augmented fifth), becoming C-E-G♯. In other words the top note is raised a half step.

If an octave from the root is added, the resulting chord (C-E-G♯-C) contains also a diminished fourth (G♯-C); this is the enharmonic equivalent of a major third, so the full-octave chord is, in effect, three major thirds.

In just intonation, the interval between two major thirds and an octave, 2/(5/4)2, is 32/25, which is flatter by a septimal kleisma of size 225/224 than the septimal major third with ratio 9/7. While septimal meantone temperament tempers out the septimal kleisma, some other temperaments, for example miracle temperament, do so also, and in all of these temperaments the augmented triad may be identified with a circle of two major and one septimal major thirds, making up an octave.

The augmented triad on the fifth scale degree may be used as a substitute dominant, and may also be considered as ♭III+, for example in C: V+ = G-B-D♯, ♭III+ = E♭-G-B♮, and since in every key: D♯ = E♭, they are the same three pitches.

Examples of popular music songs featuring the augmented chord include its introductory use in Chuck Berry's "School Days", Aaron Neville's "Tell It Like It Is", The Beatles' "Oh Darling!", after intros in Gene Pitney's "Town Without Pity", Beach Boys' "The Warmth of the Sun", Joe Cocker's "Delta Lady", at the end of the bridge in Patience and Prudence's "Tonight You Belong to Me", The Caravelles' "You Don't Have to Be a Baby to Cry", The Beatles' "From Me to You", The Dave Clark Five's "Glad All Over", and Martha and the Vandellas' "Dancing in the Street".

Other examples of the augmented chord include its use as a chromatic passing function over the first degree, the fifth rising to ♯5 then 6 harmonized as IV, as in Jay and the Americans' "Some Enchanted Evening", Lesley Gore's "It's My Party" (I—I+—IV—iv) (see also minor major seventh chord), Herman's Hermits' "There's a Kind of Hush" (continues to ♭7 harmonized by Im7), by ii Roy Orbison's "Crying", followed by 6—♭6—5 motion in "Crying", The Guess Who's "Laughing", Dave Clark Five's "Because" (verse: I—I+—vi—Im7...ii and cadence on V+), The Monkees' "Tapioca Tundra" (I—I+—vi, and V+ after bridge). Though rare, the augmented chord occurs in rock music, "almost always as a linear embellishment linking an opening tonic chord with the next chord," for example John Lennon's "(Just Like) Starting Over" and the Beatles' "All My Loving". Thus with an opening tonic chord an augmented chord results from ascending or descending movement between the fifth and sixth degrees, such as in the chord progression I—I+—vi.