If you want to play a great dark and dramatic rock guitar riff then the phrygian mode is the one to choose. It gives your riff and sound this dark, dramatic and cinematic effect which you might are looking for. In this tutorial I show you a selection of riffs and ideas which you can use for a rock guitar riff with the phrygian mode. In this case it's E phrygian. The backing track is a creation from my experience as a composer for TV and movies. I was a Hollywood composer some years ago before I became a YouTuber.
Here you can download the files associated to this tutorial :