movement

There's a thing in music called movement. A kind of movement is realized when the story to a song unfolds as you sing or chant the words. A good story begins at the beginning, then takes you somewhere. And then it takes you back home again. 


A similar kind of movement is takes place when one organization of sounds changes into another organization. And then changes back again. 


A song is happening when a progression of words and a progression of sounds are moving forward together. And a good song writer composes each of these lines of movement so that they get along really well. Or at least, stay out of each other's way. 


So one way to say it is, language and organized sounds are the building materials of songs. Let's leave the words alone for a minute and concentrate on guitar. The materials we're exploring here are common and have been with us for a long time. Everybody uses them to make all kinds of new songs. Or to make old songs new again. 


We already know how to finger the chord form that will make D major when sounded. A good question: Where do we go when we want to put the sound of D major into some kind of motion?


Answer: A seventh.


Why? Who knows?


As you become more aware of how sounds are organized in our part of the world, so will clues begin to appear which will help you to answer this for yourself. For now though, let's say that D is your house and that A seventh, or A7, is the place where you got your guitar. 


So, beginning your piece by strumming four measures D, and continuing by strumming four measures A7 would be to say that you've gone musically, from your house to the place where you got your guitar. 


We can write your little journey down on paper. Each chord symbol represents one measure. Each D symbol means four beats, or four strums of D. Each A7, four beats or four strums of A7.


D    D    D    D


A7  A7  A7  A7


But how do we get back home?


One solution is to simply slap out another measure of D, so the entire piece, or progression, is nine measures in duration. See how you like it.

D    D    D    D

A7  A7  A7  A7  D

To some ears, this progression lacks symmetry. Another way to say it is it sounds lop-sided. To play a D chord the eighth measure instead of A7 is the more common solution. This resolves our journey. This gets us back home within the very common format of eight measures. See if you like this chord progression better:

D    D    D    A7

A7  A7  A7  D

To keep the structure in segments that are four measures in duration is to say the structure is regular. Nice and even. There are plenty of exceptions of course, but this is how it's done most of the time - nice and even. 

So when D is the place to begin, A7 is the place you're going. And then you come back to D. These two chords are related as such when you begin on D.