Altered Dominants on Piano

What do altered dominants sound like?

Controlled chaos — a dominant with its 5th and/or 9th bent out of shape. Alt chords snarl, smear and then resolve like nothing happened.

How are they built?

A dominant 7 with altered extensions: ♭9, ♯9, ♭5/♯11 or ♯5 in place of the natural tensions. The 3rd and ♭7 stay put — the frame holds while the paint melts.

What is their job in a progression?

Maximum-tension dominants: every altered note is a half step from a note of the target chord, so V7alt → I resolves with every voice sliding one semitone. Tension buys smoothness.

Where you'll hear them

Bebop and post-bop turnarounds, the ♯9 IS the Hendrix chord ("Purple Haze"), gospel preachers' final V, and any ii–V that wants drama before the payoff.

The beginner mistake

Altering the wrong notes. The 3rd and ♭7 NEVER alter — they define the dominant. If those move, the chord stops functioning; only 5ths and 9ths bend.

Fingering logic

Most alt voicings are four-note grips (3rd-♭7 core + two alterations): 1-2-3-5 with the alterations on 2 and 5, keeping the defining tritone anchored under 1 and 3.

Neighboring families