The Altered Dominant

The altered dominant is a Dominant Seventh Chord pushed to its maximum tension before it resolves — every note that isn’t the root, 3rd, or 7th gets chromatically bent away from “home” so it can snap back by half step. It exists because dominant chords already want to resolve; alterations just turn up the pressure, making the eventual landing on the tonic feel inevitable. Written as G7alt, D7alt, and so on, it’s less a fixed chord than a license: stack whichever of the four altered tensions you want, as long as they resolve.

What Counts as an Alteration

Only four notes qualify, and they always target the 9th and 5th — the two Chord Extensions a dominant chord can bend in either direction without losing its dominant identity.

♭9 and ♯9 (the altered 9th, up or down)
♭5 (same pitch as ♯11) and ♯5 (same pitch as ♭13)

G7alt keeps its Guide Tones — B (3rd) and F (7th), the notes that actually define “dominant” — and replaces the natural 9th and natural 5th with some or all of these four Chord Alterations. The natural 5th (D) is usually dropped from voicings entirely, since it doesn’t pull anywhere and just dilutes the tension.

Where the Notes Come From: The Altered Scale

You don’t have to memorize four alterations in isolation — they’re all sitting in one scale. The Altered Scale is the 7th mode of The Melodic Minor Scale: to get G altered, play A♭ melodic minor starting from its 7th degree.

G altered scale: G – A♭ – B♭ – C♭ – D♭ – E♭ – F
Function: 1 (root) – ♭9 – ♯9 – 3 (C♭ = B) – ♭5/♯11 – ♯5/♭13 – ♭7

Here’s the scale ascending, with the enharmonic C♭ spelled as B natural:

Every “wrong” note in that scale is actually a chosen tension, which is the broader lesson of Melodic Minor Applications: melodic minor’s modes are where jazz’s spiciest Dominant Scale Choices live. Compare this to Lydian Dominant, the 4th mode of melodic minor — same parent scale family, opposite mood: Lydian dominant brightens an unresolved dominant, while altered darkens one that’s about to resolve.

Why Every Tension Points Home

The whole design of the altered dominant is Voice Leading by half step — this is what makes it the purest demonstration of tension and release in the harmonic language. Take G7alt resolving into Cmaj7 (C – E – G – B):

♭9 (A♭) → G, the 5th (down a half step)
♭5/♯11 (D♭) → C, the root (down a half step)
♯9 (B♭) → B, the major 7th (up a half step)
♯5/♭13 (E♭) → E, the 3rd (up a half step)

G7alt as an upper-structure stack

E♭b13

D♭b5

B♭#9

the four altered tensions

A♭b9

Fb7

The guide tones anchor the dominant below the divider; above it, b9 and b5 fall a half step into G and C while #9 and b13 rise a half step into B and E of Cmaj7

Stacking just those four tensions as an upper-structure voicing makes the half-step resolution audible:

Every altered tone slides directly into a chord tone of the target — nothing is left hanging. In the more common minor setting, G7alt → Cm7 (C – E♭ – G – B♭), only the ♭9 and ♭5 need to move (into the 5th and root); the ♯9 and ♭13 are already enharmonically the same pitches as Cm7’s ♭3 and ♭7, so they function as previews of the minor color rather than notes that resolve.

Where You’ll Actually Meet It

The altered dominant’s home turf is The Minor ii-V-i — Dm7♭5 – G7alt – Cm7 — where Dominant Resolution into a minor tonic all but demands the darker color. It shows up in major-key The ii-V-I Progression too, as an optional flavor rather than a requirement, which is why lead sheets often just write “G7alt” or “G7♯9” and leave the exact tension choice to the player — a standard piece of chord-symbol shorthand. It’s also entangled with Tritone Substitution: G7alt and its tritone sub D♭9(♯11) share the same altered pitches (D♭ and E♭/D♯), they just resolve in opposite directions — G7alt pulls up into C, D♭9 pulls down into C. This vocabulary was codified in Bebop and carried straight through hard bop as one of the era’s signature sounds, alongside other available tensions and voicing tricks like upper-structure triads built on the altered scale.

♫ Listen

Bill Evans Trio — “Autumn Leaves” (Portrait in Jazz, 1959): the minor ii-V-i turnarounds are voiced with clear ♭9/♯11 color; listen to how the alterations resolve tightly under Scott LaFaro’s bass line.
John Coltrane — “Moment’s Notice” (Blue Train, 1957): the tune’s chain of fast ii-V-i’s forces altered-scale runs into the melodic lines — listen for ♭9 and ♯9 threaded through the eighth-note phrases.
Sonny Rollins — “Strode Rode” (Saxophone Colossus, 1957): a hard-charging original where Rollins leans on altered colors over the dominant chords, resolving each tension cleanly into the next change.