The Phrygian mode is the same as the natural minor scale, with the 2nd tone
flattened. The scale has a Spanish feel about it and can be difficult to manage.
In the key of D, the flattened 2nd is the Eb, which means that the
A chord (dominant chord) has a flattened 5th.
In the key of D, this presents the notes: A C Eb (Adim). In DADGAD it
is common to rest on the A chord, perhaps in the middle of a melody. Because of
the flattened 5th in this chord, which makes it a diminished triad, it is not
such a comfortable place to rest anymore.
The scale has great benefit in providing a fingering pattern and chords for
the Bb major scale and the G natural minor scale.
