Mixolydian

A dominant chord that never resolves

Stack thirds on the first degree of Mixolydian and you get a dominant seventh chord: G B D F in G Mixolydian. In a major key that chord would be unstable and would resolve to C. Here it is the tonic, and the mode exists precisely to describe music that sits on it without going anywhere.

That single fact explains where the mode turns up. Blues-based rock, most static funk vamps and a great deal of Celtic dance music all rest on a dominant chord for bars at a time, and Mixolydian is the scale that fits without contradicting the flat seventh.

One note from the major scale

Compare G Mixolydian with G major: the only difference is F natural instead of F sharp. That is the whole mode. For a guitarist who knows the major scale it costs one note, and the fastest way to hear it is to play a major scale over a dominant chord, then flatten the seventh and play it again.

The removed leading note is what changes the feeling. In major the seventh degree pushes upward onto the tonic; in Mixolydian it steps down towards the sixth, and the music loses its urge to conclude.

Where it is heard

Rock riffs built on a major chord with a flat seventh, whole genres of dance tune, and film cues that need brightness without formality. In jazz it is the default scale over any unaltered dominant chord in a two-five-one, which makes it one of the two or three most used scales in the idiom.

In folk repertoire it is often not a choice at all but the natural shape of the melody, and the harmony that gets added later is what makes it look modal in retrospect.

What it is confused with

Plain major, one note away, and the blues scale, which shares the flat seventh but adds the flattened third and fifth. A common practical mistake is playing the major pentatonic over a dominant chord and expecting the mode to appear: it will not, because the pentatonic leaves out the seventh entirely.

The second confusion is functional. A dominant chord inside a progression usually wants an altered scale rather than Mixolydian; the mode belongs where the chord stays put, not where it resolves.

The rest of the family

Mixolydian is the fifth mode of the major scale, so G Mixolydian and C major share the same notes. Its neighbours are Ionian, which restores the leading note, and Dorian, which is a minor mode with the same flat seventh. Hearing Ionian, Mixolydian and Dorian from one root shows how much a single degree changes.

Frequently asked questions