Gbaug

Construction

Built from these intervals: 1-3-#5.

The natural 3 provides major-chord brightness. The #5 pushes the fifth up a half step from its natural position, creating upward tension. Each note sits a major third -- four half steps -- above the last, dividing the octave into three equal parts. This symmetry means only four distinct augmented triads exist. The major triad is the parent chord -- aug raises its 5 by a half step.

Harmonic Function

In Roman numeral analysis (uppercase = major, lowercase = minor):

• V+ (augmented -- raised 5th) -- dominant with a raised fifth, the #5 resolves up by half step to the 3rd of I, creating chromatic voice leading into the tonic
• III+ in harmonic minor -- raising the 7th scale degree creates an augmented triad on the 3rd degree, with the #5 acting as the leading tone pulling toward the root of i
• Passing chord -- connects diatonic chords chromatically, as in the ascending line I-I+-vi where the 5 rises through #5 to the 6th
• Multi-directional resolution -- symmetry allows the chord to resolve to three different tonics, since each note can function as the root reinterpreted in a different key

Character

Bright and precarious. As a member of the triad family, the aug chord shares the natural 3 with the major triad, but replacing the natural 5 with #5 trades grounded stability for upward strain. The whole-tone scale (a scale built entirely from whole steps, with no half-step pull) shares this floating, directionless quality -- think of film scores reaching for an unresolved climax.

Related Sounds

• maj (1-3-5) -- natural 5 instead of #5, grounded where aug is restless
• 7#5 (1-3-#5-b7) -- adds a b7 for augmented dominant function, resolves with even more chromatic pull
• maj7#5 (1-3-#5-7) -- adds a major 7, bright and lush with double upward tension
• dim (1-b3-b5) -- the opposite symmetry, built from minor thirds instead of major thirds, dark where aug is bright
• Pairs with the whole-tone scale, which contains two augmented triads and shares the chord's symmetric, floating quality

Voice Leading

Voice leading tracks how individual notes move from one chord to the next. The #5 naturally pulls upward by half step, giving every resolution an ascending chromatic voice.

• V+ to I: The #5 moves up a half step to the 3rd of I. The 3 moves up a half step to the root of I. The root holds as the 5th of I (common tone). The raised fifth resolving up is the chord's signature motion.
• V+ to vi (deceptive): The root moves up a whole step to the root of vi. The 3 moves up a half step to the b3 of vi. The #5 moves up a half step to the 5 of vi. Every voice ascends, and the half-step motions in the upper voices make the deceptive resolution feel smooth despite the surprise.
• Chromatic shift: The root moves up a half step, the 3 moves up a half step, the #5 respells enharmonically. The entire chord shifts upward -- a technique that exploits the chord's inherent upward pull.

These movements apply in any key — the intervals are the same regardless of root.

Practice Seeds

Symmetry check. Play any augmented triad, then reinterpret it from its 3 and #5 as alternate roots. Same three pitches, three possible roots. Recognizing this ambiguity is key to using the chord creatively.

Aug vs. major. Play a major triad, then raise the 5 by a half step. That single change dissolves the stability -- training your ear to hear the #5 is the foundation of understanding augmented harmony.

V+ resolution. Practice V+-I in several keys, listening for the #5 moving up to the 3rd. This ascending half step is the most common and satisfying augmented voice leading.

Chromatic line. Play I-I+-vi, listening for the 5 rising through #5 to the 6th. This ascending chromatic bass line appears in countless songs and reveals how augmented chords connect diatonic harmony.