C Phrygian

The C Phrygian mode — C Db Eb F G Ab Bb — shown across the guitar neck.

Swipe the neck sideways to see the higher frets.

C Phrygian is the natural minor with one note changed — the b2, Db. That single note is what the mode sounds like; lean on it and the colour is obvious, avoid it and you are just playing minor.

The tool shows this from its parent key, Ab major, with C marked as where Phrygian begins, the same seven notes centered on Ab.