What is the Mixolydian mode?
- Dominant scale
- KhamajखमाजHindustani thaat
- HarikambhojiCarnatic melakarta
- ≈Adonai Malakhאדני מלךJewish prayer mode
Mixolydian is the major scale with one change: the seventh is lowered a , giving 1, 2, 3, 4, 5, 6, ♭7. It is the fifth of the major scale — G Mixolydian uses the white keys of C major, started from G. The ♭7 keeps it from settling the way major does, which is why it fits blues-rock riffs and the harmonica's second position, where a C harp plays in G.
Mixolydian is the mode blues harmonica lives in. 'Cross harp' — playing a harp a fourth below the song's key — puts the draw notes, the ones that bend, on the strong beats, and the scale those draw notes spell is Mixolydian. Bend the third and fifth down and you are in the blues scale; leave them alone and you have the bright, unresolved sound of a great many rock riffs, from country-rock to the -chord vamps of funk and soul.
This page is a lesson, not a poster. Read it top to bottom; every section has something to press, and the whole page follows one root and one octave — change either and everything below changes with it. If the low keys are hard to hear on your speaker, use Octave + to lift the whole lesson.
1. First, hear it
The keyboard below is locked to G Mixolydian. Keys with a green number are in the and play; keys with a red dot stay silent. Press Play. It sounds like a major scale — bright, open — right up to the last step, where something refuses to close. That refusal is the whole mode. If you have heard a blues harmonica, a Southern-rock riff, or a funk vamp that sits on one chord for a minute, you have heard it.
2. Counting from home: one flat
Every scale has a home note, the — here G, and the picker above moves it. The other notes are named by how far above the root they sit: their . Count keys to the right, black and white alike; each key is one . The plain numbers 1 to 7 belong to the major scale; a (♭) means “that note, one key lower.”
| Degree | Half steps (keys) above the root | In G | What it is |
|---|---|---|---|
| 1 | 0 | G | the root — home |
| 2 | 2 | A | second |
| 3 | 4 | B | major third — still bright |
| 4 | 5 | C | fourth |
| 5 | 7 | D | fifth |
| 6 | 9 | E | sixth |
| ♭7 | 10 | F | lowered seventh — the changed note |
Six plain numbers and one flat. Everything through the 6 is the major scale, unchanged — the bright major third is still there. Only the seventh has moved, from one key below the root to two. Click a chip to hear each degree in G.
3. Move one key: major becomes Mixolydian
Take the major scale in G and lower its 7 — F♯ — one key to F. Nothing else changes. Flip the toggle and watch one key go dark while its lower neighbour lights; play both runs and listen to the top of the scale. Major climbs the last step and lands. Mixolydian steps off a shorter stair and hangs there.
Mixolydian keeps every other note but changes 7 (F♯) to ♭7 (F). Flip the toggle and watch one key go dark while its neighbour lights up.
Why does one key matter so much? In the major scale the 7 sits a single key below home and leans into it — the leading tone, the note that makes 7 → 1 feel like arriving. Mixolydian has no leading tone. Its ♭7 is two keys away and does not lean anywhere in particular. Press both pairs and hear the difference: the first one arrives; the second one just moves.
4. What the ♭7 gives back: the dominant chord
Losing the leading tone sounds like a loss, but the ♭7 buys something. Build a chord on the root — 1 3 5, a plain major — and add the ♭7 on top. That four-note chord is a , the sound of a blues chord, a rock-and-roll chord, a funk vamp. In the major scale that chord only lives on the fifth degree, where it pulls toward home. In Mixolydian it lives on home, so the pull points at the chord you are already on. The music leans and never falls; it can sit on one chord as long as it likes.
5. Same keys, different home: a major scale from its fifth
Now the map view. Take the seven keys of G Mixolydian and, without turning any on or off, call the 4 home instead. You are now playing the major scale on C. In G that is C major: the same white keys, settling one note lower. Flip the toggle and only the green 1 moves.
G mixolydian uses exactly the same keys as C major. Nothing turns on or off — only 1 moves. Home is now G, which was the 5 of C major. Play both runs and hear how the same notes settle in a different place.
Western theory calls Mixolydian the fifth of the major scale — the major scale started from its fifth degree. That is true of the notes and useful on a keyboard: any tune you can play in C major you can play in G Mixolydian with no new keys. It is also the reason the harmonica gets involved.
6. Why blues harmonica lives here: second position
A ten-hole diatonic harmonica is built around one major scale — a “C harp” blows and draws the notes of C major. Play it in C and you get the major scale: first position, straight harp. But most blues players pick up that same C harp and play in G — the key a fifth up. The notes have not changed. The home has. A C harp played in G is playing G Mixolydian, and that is second position, cross harp, the position most blues harp is played in.
Two things make it work. The ♭7 is already there, so the scale matches the dominant-seventh chords of a blues. And on a harp the notes that can be bent — drawn and pulled down in pitch — are the draw notes, and in second position the draw notes land on the strong degrees. Bend the 3 down and you get the ♭3; bend the 5 and you get the ♭5. Those are the two , and with them the player slides from Mixolydian into the blues scale. Flip the toggle to see which notes each scale has that the other lacks — a harp player moves between the two constantly.
Mixolydian adds 2 (A) and 3 (B) and 6 (E) and drops ♭3 (B♭), and ♭5 (D♭). Flip the toggle and count the keys that change hands.
A piano cannot bend, so this keyboard shows the two scales as separate lists. On a harmonica they are one instrument’s worth of notes and the bends in between. The Harmonica Lab shows exactly which hole and which bend gives each note in second position, for any key of harp.
7. What to do with it
Keep the lock on and play the green keys over a single held root — Mixolydian is a one-chord mode, so you do not need a progression to make it work. Land on 1, 3, or 5 for a settled note and ♭7 for one that leans. Try ♭7 → 1 and ♭7 → 6 as phrase endings; both are more relaxed than the major scale’s 7 → 1. Then read What is the blues? for the form this mode was built to sit on.
Quick reference
- Formula
- 1 – 2 – 3 – 4 – 5 – 6 – ♭7
- In G
- G – A – B – C – D – E – F