D Mixolydian

The D Mixolydian mode — D E F# G A B C — shown across the guitar neck.

Swipe the neck sideways to see the higher frets.

D Mixolydian is the major scale with one note changed — the b7, C. That single note is what the mode sounds like; lean on it and the colour is obvious, avoid it and you are just playing major.

The tool shows this from its parent key, G major, with D marked as where Mixolydian begins, the same seven notes centered on G.