Beginning chord theory

'51 Deluxe amp, '82 reissue '62 strat

Last time, we discussed what chords substitute as Major, Minor and Seventh chords in "western" music theory. This week we will begin to explore how to build chords. Of course we are going to begin with the simple tonic chords, such as C or A or E, etc. This is easy, believe it or not. To build a three-note chord such as a tonic or major, we need to use a triad (tri=three, right?). The first note is the ROOT of the chord, and the other two are the third and fifth notes counting from the root.

The first note is C, the root. The next note is the THIRD from the root, ie, E. The next is the FIFTH note from the root, G. So if you play the three notes C-E-G you have a C chord. The number from the root is called an interval, and by using the third and fifth interval we just made a chord. Easy, see?

That's all there is to it?

Well, almost. In the key of C that's all there is to it, because in the key of C there are no sharp or flat notes. But in other keys there are, of course, so we must go just a little deeper into this theory thing.

As I said in the first lesson, I am (right or wrong) assuming that you already know a little somthing about music, like that fact that there are 8 notes with 12 tones in an octave. If not, bear with me. If you are thinking this lesson is ridiculously easy so far, hang on, we're about to get into something a little deeper.

There are eight notes in an octave, A-B-C-D-E-F-G. In between are sharps (also called flats, depending on if you are going UP or DOWN the scale), for a total of 12 tones. Why aren't there 16? Because between B and C there is no sharp note (or half-step), nor between E and F. From note to note is whole-step, from tone to tone is half-step. So the musical scale is:
A-A#(#="shapr")-B-C-C#-D-D#-E-F-F#-G-G# and back to A.

Now, the entire structure of "western" music theory is based on this scale in the key of C. The steps in the key of C are:
C-C#-D-D#-E-F-F#-G-G#-A-A#-B-C. But the musical scale of a key does not involve playing twelve tones, it involves playing the OCTAVE, or the eight notes. This is where we get "Do-re-m-fa-so-la-ti-do" from, for those of you driven crazy by "The Sound of Music". So the 8 note scale in the key of C is:
C-D-E-F-G-A-B-C, that is to say the scale with NO sharps or flats. So the intervals are:
whole step-whole step-half step-whole step-whole step-whole step-half-step. Count the whole- and half-step tones in the key of C and this is what you arrive at.

Just what does all that mean?!?

Well, it means we are just about to learn how to make triads in any key. We made a tonic C chord by using the root and the third and fifth interval to make a chord of the notes C-E-G. But what if we wanted to make the tonic chord in the key of A? If we count the third and fifth note we end up with A-C-E, but if you play that chord it won't sound like an A chord, because it isn't. That's because in the key of A there are sharps and flats, and so we need to count the INTERVALS, not the notes. And the intervals are always the same in every key, that is, whole step-whole step-half step-whole step-whole step-whole step-half step. So the intervals (or the musical scale) in the key of A is:
A-B-C#-D-E-F#-G#-A, which, if you count them up among the 12 tones is the whole step-whole step-half step-whole step-whole step-whole step-half step we were just talking about.

This interval stepping process is constant through every key. Therefore by counting the whole and half steps in the same order in any key you can determine which notes are sharp and flat in each key, so you can see what the major scale is in each key AND determine how to create chords by intervals in each key. So, as we count like above, we see that the A chord is A-C#-E, in other words, ROOT, THIRD and FIFTH intervals. In the key of B it would be B-D#-F#, in D it would be D-F#-A, and on and on.

Note that this works for all keys, including the sharps and flats. The tonic chord in the key of G#, for instance, is G#-B#-D#, in D# it is D#-G-A#. You could call G in this instance, F##, but that's for another lesson.

Now this is an important point: this is the same method by which NUMBER CHARTS are made for studio work in Nashville TN, and are also used in many other areas of the country (and world) now. When we get to making more chords, such as the standard tonic-dominant-subdominant chord progressions, you will see that the same system of numbering the intervals can be used to determine not only which notes are sharp and flat in each key but in the system of writing out chord changes by number instead of key. By writing a chart in numbered intervals between the chord changes, you can change the key of the song and simply adjust which chords you are playing without having to rewrite all the charts in musical notation. This saves a lot of time and effort, and is becoming the standard method for studio work. So if you are interested in an actual career in music, this is something you NEED TO KNOW.