Perhaps this has been thought of or discussed before. It probably has but if so, I have not seen it.
I was prepping for an upcoming jam and practicing vamping/rolling to songs I expect will come up. I don't know if it’s just me, but one of the many things I really struggle with is to remember all these different chord progressions. The fact they are similar almost makes it worse somehow. And when I’m trying to learn multiple songs for a jam I can get really mixed up. At least until I came upon this idea.
Using the Nashville Numbering System- or some might say abusing it - I began with the starting assumption that many people view going I->IV as a 'brightening' or kind of accelerating feeling and I->V as 'downshifting or braking'. Inexact perhaps, but helpful in the following context.
What if the ‘I’ becomes a sort of baseline, IV (brighter) is 'higher' and V is ‘lower’ ('braking' in this case means it gets a negative 5), sort of following the Nashville Numbering System. If you can buy into that single idea, then you can create a pictorial representation of a I-IV-V chord progression like this example of Worried Man Blues.
This I at least, have a much easier time keeping in my head. Even If I can't remember the exact measure counts I know about when something is going to change and how it will change.
Here is another for Jesse James
I could show some others but you get the idea. You would of course need more points to show a song like Cripple Creek with mid measure chord changes (at least in Excel) But I think more utility can be garnered here by keeping it simple; this could all be drawn on a napkin. With practice I think that if somebody calls out 4 bars of G, 2 of C, 4 of G and 2 of D 4 of G, you should be able to at least put a low resolution mental image in your head to help get you through the song.
This like the numbering system itself takes care of unexpected keys as you begin to think of things in terms of song effects as opposed to letters or even numbers.
I suspect if anybody at all would find value in this it would be relative beginners like me. We relative newcomers are all trying put so much new stuff in our heads that anything that makes the process easier is worth at least a try. Please don't let this be a crutch. Far better is to hear and recognize the chord changes. But I think you can use this to learn to hear them better. It helps when you know they are coming.
If you think it worthy give it a try.