Who said Blues music is "simple"? Beyond the old 12-bar "standard" Blues chord progression, many Blues and Jazz players have written Blues songs with incredibly complicated chord changes. Many beginner and intermediate players are intimidated by them, but as we will see in the following, they are quite easy to understand and even easier to play. How is that possible? Keep reading.
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 intimidating 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.)
The good news is that it does not need to be this way. No great Jazz player needed a Phd in Applied Mathematics in order to understand substitutions, and neither will you. The problem is not in the rules per se: they are quite easy if explained in the right way. The problem is, indeed, in the explanation. Once you figure out why these rules work and what they mean on the fretboard, they are surprisingly easy.
I have recorded a video (below) where I will show you one of the most "feared" substitution rules - and you will see that it's incredibly easy. So easy that you will be able to improvise using it. I will apply it to a Blues chord progression, but you can of course apply it to any dominant chord.
Watch the video and see how easy this all is.
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.
Tommaso Zillio is a professional prog rock/metal guitarist and composer based in Edmonton, AB, Canada.
Tommaso is currently working on an instrumental CD, and an instructional series on fretboard visualization and exotic scales. He is your go-to guy for any and all music theory-related questions.