The major pentatonic has five notes and two gaps. Fill them with the fourth and the ♭7 and you have a seven-note scale: mixolydian. It is worth a lesson because those two notes are not arbitrary. The ♭7 is what makes a dominant seventh dominant, and the scale is where the chord comes from.
Mixolydian on the neck
57 notes of the A mixolydian scale are marked across six strings.
This is every place the notes of the A mixolydian scale fall on the guitar, with each note's name and its scale degree. The roots are marked so you can find your bearings.
Every note of A7 is in there — A, C♯, E and G — with three more filling the spaces between them. Play it over an A7 and nothing you land on will sound wrong, because everything in the scale belongs either to the chord or to the steps between its notes.
The same seven on a keyboard
The keyboard shows the same seven notes as a shape you can see. The colored keys are the A mixolydian scale.
On a keyboard it is the major scale with one note lowered, and that note is the ♭7. That single change is the difference between a scale that wants to resolve and one that can sit on a dominant chord for twelve bars, which is what a blues asks it to do.
What it gives you that the pentatonic does not
Two notes, and both are useful. The fourth is a step below the chord’s third and leans onto it. The ♭7 is the chord’s own seventh, so it is a place to stop. Between them they let a line move by step rather than by leap, which is what makes mixolydian sound smoother than a pentatonic and, played carelessly, blander.
The catch is that mixolydian belongs to one chord. The scale that fits A7 has a C♯ in it, and over D7 that note leans hard. Players who use it move it with the chords — a different mixolydian for each — which is a different way of playing from the one box that Parts 2 and 3 taught.
This lesson was drafted with the help of AI, so it may contain a mistake. Its diagrams are drawn by Everyfret’s own software. How Everyfret is made