G Phrygian scale on the guitar fretboard
The G Phrygian scale is made of G (the root), Ab (minor second), Bb (minor third), C (perfect fourth), D (perfect fifth), Eb (minor sixth) and F (minor seventh). The fretboard shows every one of them across the neck in standard tuning (E A D G B E), and plays them back so you can hear the scale.
The Phrygian mode is the third mode of the major scale, a minor scale with a lowered second. That lowered second sits a semitone above the root on the neck. It shares its notes with a major scale a major third below.