Thanks for this. I suppose I'm being a bit simple thinking there needs to be some ironclad or even scientifc explanation why the practice is the practice, when all that's needed is for science and theory to be very consistent with a strong tendency to the practice, and to provide a language for talking about it. And then you have the out that the practice doesn't forbid deviation, but just requires extremely good execution to justify.
i-IV may not strictly mean Dorian, but a repeated vamp where that's the most of what happens, if not all of what happens in a bit of music tends to out as Dorian mode. 1) the fact of it being all of what happens in the vertical or harmonic realm and 2) the whole fabric of repeated vamp designed for 'a guitar (or what-have-you) solo' means in all likelihood modal playing. Hence, a real-world example of it working.
Critically, in itself if all we have is i-IV in a vamp (BTFW this in the Carlos Santana Secret Chord Progression as modeled it's bloody clear what is happening) 'Maybe it isn't' remains to be seen. If I land on C# here, I need to make it work or it's a wrong note. To make it work means taking it into a new area, or now we heed Miles Davis and "there are no wrong notes", ie., make it convincing.
Statistics: Posted by mjudge55 — Mon Mar 18, 2024 11:56 pm