You may have heard about Jazz Chord Substitutions. The basic idea is to take a chord progression, then change a few of the chords in order to make it more interesting, usually following some complicate-looking rules. Most chord progressions are created using substitutions on shorter and simpler progressions so once you master the substitutions you can create new good chord progression (and it's easier to understand the existing ones).
The problem is due to these complicate-looking rules. They are not as complicated at they seem, but most teachers (or books) tend to just give them out without really explaining them in detail. This is NOT helped by the fact that said teachers or books start their explanation with phrases like: "obviously C9/b5 = Gb7/#5/b5". Obviously? (and yes, this is an actual quote from a book that I will leave unnamed…)
Good news everyone: it does not need to be that way. All these Jazz players who discovered these substitution "rules" did not have to get a PhD in math in order to understand them. Which makes you think that the problem is not the rules per se, but the way that they are explained. And in fact, substitution rules are quite natural if you sit down a moment and try to understand WHY they work.
In the video below I will show you how to use one of these "scary" substitutions to make a standard Blues progression sound like a complicated Jazz. Best of all? It's easy, so easy that once you see what I'm doing you can IMPROVISE the chord shapes rather than using chord shapes that you committed by hart.
Watch this video and you'll see what I mean.
What you should do now? Well if you haven't taken up your guitar yet, this is the time! Play everything I was playing in the video on your guitar. Get your fingers to know the few shapes I have shown, and see how easy it is to actually play them.
As you can see, you can apply the substitution straight on the fretboard, without "calculating" what chord you have to play. Just play one chord shape rather than the other. THIS is how great Jazz player do it! Of course, there is MUCH more to substitutions than what I explain here (book have been filled with them), but now you have an idea of how to understand them: see what they mean directly on the fretboard.
About the Author:
Tommaso Zillio is a prog rock guitarist and teacher with a passion for Music Theory applied to Guitar.