Mixolydian Augmented

The chord that gives it a job

Stacking thirds from the root produces C E G♯ B♭, an augmented dominant seventh written C7♯5. Every other note of the scale is an available tension in its plainest form: D as the ninth, F as the eleventh, A as the thirteenth, none of them altered.

That combination is what makes the mode worth knowing. Most scales that supply a 7♯5 alter something else at the same time, so a player who wants an augmented fifth and nothing more has few options — and this is one of them.

One note from Mixolydian

Mixolydian from C is C D E F G A B♭. Raising the fifth to G♯ gives the mode and touches nothing else, which means the dominant character survives intact: the major third and the flat seventh are both still there.

For a guitarist the practical route is the same as any single-degree alteration. A familiar Mixolydian shape, one finger moved up a fret on the fifth, and the sound arrives without a new fingering to memorise.

Why it is not the whole tone scale

The whole tone scale also delivers a 7♯5, and it is the first thing most players reach for over that chord: C D E F♯ G♯ B♭. Six notes, all a whole step apart, no perfect fourth and no sixth at all.

Mixolydian augmented keeps seven notes, keeps the perfect fourth, and keeps the natural sixth. Against a C7♯5 the whole tone scale erases the difference between chord tones and colour; the mode keeps a hierarchy, because F and A pull somewhere while G♯ sits still.

The augmented second between fourth and fifth

Raising the fifth opens three semitones between F and G♯. All seven modes of the Neapolitan minor carry exactly one augmented second, and here it sits in the middle of the scale, right where a melody usually passes through on its way up.

Practically that gap is the mode's signature. A line that walks from the fourth to the fifth cannot do so smoothly, and the leap is audible in a way the same interval is not when it hides at the top of a scale.

What it is confused with

Ionian ♯5 is the closest neighbour: C D E F G♯ A B. Only the seventh separates them — B against B♭ — and that single degree decides whether the tonic chord is a major seventh or a dominant. Ionian ♯5 belongs to the harmonic minor family, this mode to the Neapolitan minor.

The altered scale is the other frequent substitution. It also produces a 7♯5, but it flattens the ninth and removes the perfect fourth, so it fits a dominant that is straining to resolve. Mixolydian augmented fits one that is content to sit still.

Frequently asked questions