So you'll recall from the previous blog that we are learning to identify by listening to them, three important chords: the tonic chord (I), the fourth chord in the scale (IV) and the fifth chord in the scale (V).
To help you recognise these three important chords lets examine a little more closely the standard twelve bar blues progression. While there are variations on how we navigate these twelve bars the most basic version contains three lines, each of which has four bars and it looks like this:
As an exercise see if you can hear in your head the changes from I to IV and back again. And then do the same for the last line, from the V, down to the IV and finally to the I. I'm assuming that we've all heard this progression so many times that it's etched in our brains. If it's not in yours yet that's OK just grab a guitar and play it over and over again until it is.
Now, if you haven't already, grab your guitar and play the I chord in a bluesy rhythm over 4 bars and before you change to the IV chord, stop and see if you can hear it in your head first, better still see if you can sing it before you play it. Then play it to see how you went. If you can, try it in different keys, grab another guitar or retune the one you have, even a semitone.
Do the same thing with every chord change, play the IV for two bars and see if you can hear the I before heading back down. Do the same with the V chord and so on.
Tension and Release
All music has to create tension and then release it again, otherwise it's boring. The twelve bar blues progression uses these couple of cadences to do just that. Listen how the IV chord in the 5th bar creates tension which is then released with the return to the I in bar 7. This is of course the response to the opening line in which the melody usually changes but the lyric stays the same. Compare this to the extra tension created by moving to the V chord in bar 9. Here the response is a completely different one that eventually resolves strongly back to the I chord.
The structure of the twelve bar blues, particularly the cadences involving the I, the IV and the V chords create the tension that is inherent in the blues. Make sure that you can hear them in this context too, it'll help.
Finally play it again but replace the I chord in the last bar with a V chord and hear it how it sets you up, turns you around even, for the next progression.
|When you're improvising you need to stay one very small step ahead of yourself, it's important to know what the next note you play is going to sound like. This exercise will allow you to know what the next chord will sound like and eventually you'll be able to choose your notes accordingly, not by what you're told to do, or what the theory says will work, but what you want to do based solely on your own creative impulse.|