Just a random thought. But for rock music in particular, I wonder whether or not, or how rock would have evolved if the musicians who developed it had first gotten a good solid grounding in what music theory say's works. Would too much adherence to classic music theory have constrained what was done? I have read for example that alot of rock uses chords with roots from the diatonic, or a pentatonic minor scale, but with a lot of freedom as to whether or not those chords are really in the key (e.g., minor vs major, or ubiquitous use of dom7 chords that aren't really in the key). I believe that music theory can be both descriptive and prescriptive. Did music theory catch up to rock? That is, was a lot of rock not really based on music theory and may have indeed violated some principles and then music theory started working on why some of that actually sounds good? Maybe not. I don't know. Just wondering really.

I was noodling around the other day and was surprised that the following progression sounded quite nice: D(D form)->F#(E form at 2nd fret)->G(G form at 3rd fret)->A(any position). The F# isn't in the key of D, it's not a borrowed chord from any of the modes, it is a secondary dominant of the diatonic Bm Chord but it doesn't resolve in a way that suggests to me with my limited understanding that it's acting as a secondary dominant. It's maybe best thought of as an altered diatonic F#m that I just decided to make major instead. OK, sounds nice. I wouldn't have come up with that based on the little I know about music theory. Maybe if I knew more about music theory I would have though. Well, I've got a lot of time on my hands to think about these things I guess.