The Augmented Dominant

Take an ordinary Dominant Seventh Chord and sharpen its fifth by a half step, and you get a chord that pulls toward resolution harder than a plain V7 ever could. That raised 5th is a note straining upward, adding a second chromatic lean — on top of the tritone between the 3rd and ♭7 — that intensifies the Tension and Release every dominant chord exists to create. It is one note moved a half step, with an outsized effect on how urgently the chord wants to land.

Why Sharpening the Fifth Sharpens the Pull

A plain G7 already does most of its work with two notes: B (the 3rd) wants to rise to C, and F (the ♭7) wants to fall to E, and together they form the tritone that defines dominant function. Raise the 5th from D to D♯ and you add a third voice with its own upward pull, behaving almost like The Leading Tone but chromatically, since it sits a half step below the note it wants to become. The result is a chord that sounds less settled and more insistent than a plain V7 — exactly why it turns up at moments that need one extra jolt, such as turnarounds and cadence points just before the tonic lands.

Spelling and Notation

G7♯5 = G–B–D♯–F (major triad with a raised 5th, plus a minor 7th)
Also written G7+5, Gaug7, or G+7 — all the same chord
C7♯5 = C–E–G♯–B♭
F7♯5 = F–A–C♯–E♭

The ♯5 and ♭13 labels point at the same physical pitch (D♯ and E♭ are enharmonic twins), but jazz Chord Symbols convention treats them differently in practice: call it ♯5 when the raised fifth functions as a core chord tone inside a triad-based dominant, and reserve ♭13 for contexts where that same pitch is voiced as a stacked upper extension. Most lead sheets simply write ♯5 for this specific sound, saving ♭13 language for the denser The Altered Dominant palette.

Here is that G7♯5 spelling stacked as a close-position voicing:

Where It Resolves

G7♯5 → Cmaj7: G–B–D♯–F → C–E–G–B (D♯ rises a half step into the major 3rd)
G7♯5 → Cm7: G–B–D♯–F → C–E♭–G–B♭ (D♯ respelled as E♭ — already the minor 3rd of the coming tonic)

That second resolution is the elegant trick of the augmented dominant. In a The Minor ii-V-i, the ♯5 barely has to move at all, because D♯ and E♭ are the same key on the piano — the pitch simply gets relabeled. What sounded like a restless ♭13 over G7 becomes the settled minor 3rd of Cm the instant Dominant Resolution lands, so the tension resolves as much by reinterpretation as by motion. That’s part of why V7♯5 feels so natural gliding into a minor tonic.

The D♯ rising a half step into C major’s 3rd:

The Whole-Tone Connection

Every note of G7♯5 lives inside one Whole Tone Scale: G–A–B–C♯–D♯–F. That’s not a coincidence — an augmented triad, G–B–D♯, is itself built entirely from whole steps, so The Augmented Triad and the whole-tone world are really two views of the same symmetry. Improvisers treat V7♯5 as an open invitation to run whole-tone lines, since nearly every note in the scale is either a chord tone or a smooth passing tone — one of the rare cases in Dominant Scale Choices where the “right” scale is obvious just from the chord spelling.

G7♯5 (amber) sits entirely inside one whole-tone scale, with its augmented triad G–B–D♯ inscribed as an equilateral triangle of major thirds

A whole-tone run built from that same G7♯5:

7♯5 vs. the Fully Altered Dominant

V7♯5 raises exactly one note. Stack a ♭9 and/or ♯9 on top of that same raised 5th and the chord becomes the fully The Altered Dominant — denser and more dissonant, drawn from the altered scale rather than the whole-tone scale. Think of V7♯5 as the single, stark alteration that gives augmented-dominant color its identity, and the fully altered chord as what happens once more tensions pile on top of it. They’re cousins, not synonyms: 7♯5 keeps an open, symmetrical brightness that the fully altered chord trades away for maximum crunch, a distinction worth hearing clearly in Voice Leading before combining them.

♫ Listen

Thelonious Monk — “Ruby, My Dear” (Genius of Modern Music, recorded 1947): listen to the cadences under the melody — dominant chords with raised fifths give this ballad its bittersweet, leaning quality throughout.
Thelonious Monk — “Straight, No Chaser” (Blue Note, 1951): Monk threads whole-tone runs — the melodic face of the augmented dominant — through his solo choruses, cutting sharply against the otherwise straightforward blues changes.