Using superstition as an example, and to make things easier lets say its in E rather than Eb. Most of the song is based around that pentatonic riff and that pentatonic riff is where my question/discussion is geared towards. The pentatonic riff is complamented with a dom 7 chord, from what I understand you can play almost anything over a dominant seven chord, like a pentatonic, blues scale, mixolydian, Dorian etc. I like to jam Dorian over it. So if I am playing Dorian over it can I consider it a ii chord and continue to play in the key of D major over the riff. I have recorded myself playing in the key of D along to a backing track in E. I like the results. Does anyone do this or am I stumbling around. My train of thought is, the riff doesn't have any sixth notes be it major or minor. So it could be approached as an aeolian making it the relative minor of G or what if I solo a Dorian over that dom7 making it the ii of D because Dorian is the second mode of a major scale. All the notes in e Dorian would be in D Ionian. Does the E7 chord really dictate what's going on or is the riff what is in charge of the phrase.