The quartet concept is very similar to the Trinity concept. But the Trinity concept is based on the augmented chord. The quartet concept is based on the diminished chord.
A problem that I am running into frequently is that many people in this world care more about names than what the names mean. I just ran into a problem about modulation vs key change. It turns out that musicians all over the world all use these terms in different ways. Some use them exactly as I do. Others don't. I just read a discussion that goes on and on forever we're basically no one agrees with anyone else. So what I am trying to present is a practical idea. Are in one place and you want to get to another place. You can go to that other place for justice a couple of seconds or for a year. Or for a lifetime. Once you go to that other place you are free to stay there for a short time or a long time before you return to where you started. Or you can continue going to new places without ever returning to your starting place. I just wish someone would make music as easy as Dr Seuss made reading!:)
I am finding these principles in composers from Bach to Rachmaninoff. I don't know how they learned these things. It seems to just be what we absorb in patterns from playing music, writing music and improvising music. For instance I just spent a couple of weeks with the Mahler Second Symphony, the one with the nickname "Resurrection." First of all,, I found a spectacular performance by Bruno Walter on You Tube. And of course that shows how lucky we are today to be able to hear such performances for free. I don't know about you but I don't buy any recordings until I've heard them, because they are simply too expensive to take a chance on going merely on their recommendation of other people. So once I heard this performance and knew how good it was I ordered it and it just arrived for my own personal collection. It is an amazing recording. But while spending time getting to know this amazing Symphony even better I discovered that even though he starts out in C minor, soon he is in a flat major for just a little bit. Then his second theme goes to E major. The number of keys that he gets to in only the first movement is dizzying. None of the things that I was taught in school begins to describe what he does in this piece. But I can tell you that even though he is in the key of C minor it's not long before he visits E flat minor F sharp minor, and a minor. And there is the quartet idea. Of course he does not limit himself to that because in this first movement at some time or another he hits every possible major and minor chord that exists come all 12 of them. So after decades of studying this stuff and trying to present it to students I am still learning even more about how these geniuses composed and still composed.
Maya, this stuff is about musical grammar. Or we could call the grammar that you learn in school word theory. Musical grammar doesn't necessarily make us play better or write better music. But there is a chance it will. And also the more that you know about how music works, the more it brings your consciousness to an active level as you are listening and you start to appreciate music on a higher level.
It's interesting that when you combine the Trinity process with the Quartet process you get a huge amount of the possible transpositions that we always have available. If we start in the key of C, then E and A flat, now it gives us 3 keys. When we add to that Eb flat, F sharp, and A we now have 6 keys. That's half the keys we can use. When we add to that the circle of fifths to degree IV and V, we now have 8. By going up or down a tone or a half tone we add the other four and we have a way to get to everything in the universe.
