Foxy's Guitar Lessons

A GUIDE TO
UNDERSTANDING
GUITAR "THEORY" ©

LESSON SEVEN: TETRA-CHORDS (and some Basic Chord INFO...)

TETRA-CHORDS : What are they and how they can dramatically change your "Understanding" of WHICH CHORDS GO WITH ANY "Selected" KEY?

The RULE is simple : "TETRA-CHORD" (actually written: tetrachord) means A succession of "Four" naturally occuring tones (which is the basis for Scale construction).
To explain this, observe the following example :

TETRA-CHORD = 1st Half of a Scale

We START at "C" and count a Total of 4 notes.. C D E F. That's it ! See simple !

TETRA-CHORD = 2nd Half of a Scale

Next, we "add" another "TETRA-CHORD" (The NEXT 4 "naturally occuring" NOTES), Which in this particular KEY, just happens to be : G A B C.

Notice that we END on "C" again.

Put this all together and the following "Major" scale is composed :

1st Half (Both Halves = Major Scale) 2nd Half (Both Halves = Major Scale

RULE : It requires 2 Tetra-Chords to make a Major Scale

Now we have a "C" Major Scale ! There are now 2 "tetrachords" TIED together. The next step is to assign a NUMBER TO EACH NOTE.
1=C
2=D
3=E
4=F
5=G
6=A
7=B
8=C

The "Number Assignment" will apply to ALL Keys, only the NAMES of the notes will be changed as shown in the illustration MAP below. © 1997 MGS

A couple of "New" rules must be introduced at this point to make CLEAR the "Pattern" that is to be followed in order to make ALL Major Scales SOUND like "MAJOR" Scales (and not a variation).

(Get a Piece of Paper and write out this next EXERCISE. If JAVA is your thing, check out the PRESENTATION © 1997 MGS... at the end of this lesson. Although I "wrote" it out for you in JAVA, it is still good "practice" for YOU to write it down !)

1. First, you need to create a "1's" Place. This is where the "First" (1st) NUMBER of the "FIRST" TETRA-CHORD is placed, with the remaining Numbers falling behind it, i. e., (1) "C", (2) "D", (3) "E", etc..

(A very IMPORTANT note here... The Following RULES apply ONLY to the "Sharps" Scale. They START on the KEY of "G", and continue through "C#".)

2. When the Step Degrees are followed (1 2 3 4 5 6 7 8), you must ALWAYS "Raise" the 7th tone of the Scale when you MOVE the 2nd half of the TETRA-CHORD to the "1's" Place. This RULE will only apply to the "Sharps" Scale. (Flats have a different, but similar pattern.)

3. You MUST RETAIN the previous "Sharp" in the next "SCALE". In the "1's" Place, transfer the "Last" half of the PREVIOUS Scale, (the "G A B C" in this first example).

TetraMap courtesy of Mike Strickland

THAT'S ALL FOR NOW!
(See, that wasn't TOO painful was it?)

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