IntroductionSo, the Phrygian Dominant scale, as most guitarists know, can be derived from the Harmonic Minor scale. Specifically, it is its 5th mode (A Harmonic Minor in this case). It is a scale a lot of guitarists across a variety of genres know and love. For me, personally, it is my all time favorite scale to play in. Harmonically, though, we are faced with a problem of sorts: the chords in the scale are of the following qualities (in ascending order): major, major, diminished, minor, diminished, augmented, minor.
Since we have essentially only 4 chords that can produce the characteristic sound of the scale without creating so much tension that the backing we are playing over starts to sound unstable, we are kind of limited in the actual harmonic options we can use with a reasonable amount of freedom. For example, Phrygian Dominant backing tracks often consist of a simple E-F groove, or an E-F-Dm, or an E-Am-F... You get the idea. So if we want to play a solo using just the Phrygian Dominant, we can end up playing the same licks and runs, depending, of course, of the feel, tempo, and rhythm figures that are being used.
The Obvious ChoicesNow, I'm not saying we should avoid the scale entirely. After all, there's a reason it's one of the most popular scales in metal, and if we don't play it at all, we will sound like we don't know what we are doing. It would be like playing the blues without the Minor Pentatonic scale!
On to our options then:
Phrygian Dominant (1 b2 3 4 5 b6 b7) (E F G# A B C D)Our first option is the scale that the chords and riffs in the backing are derived from. Instantly recognisable and exotic sound.
Diminished arpeggios (1 b3 b5 bb7) (F G# B D, these notes in any orderMade popular by Yngwie Malmsteen and a lot of neoclassical guitarists, these emphasize the inherent tension of the scale (since the Phrygian Dominant is ostensibly a major scale with minor intervals). These are derived from the 2nd, 3rd, 5th and 7th degrees of the scale, in no particular order, since the diminished chord/arpeggio is a symmetrical one (stacked minor 3rds). You can either use the sweep patterns or the symmetrical 2 notes per string pattern to create a lot of interesting, tension filled lines.
More interesting choices: