Why Major Scales Play Nice With Major Chords.

Keys

How are keys made?  How do we know that in the key of C there is a C chord an F chord and a G chord?  If you are like me, a friend or family member just told you that is how it is, and you and I took that knowledge for granted; we did not question it, not for one a moment, because it is true. 

Now I'm a why guy, someone who asks, "why?" a lot! This why-ness runs very deep, so deep that I am like a little boy tugging at his mommy's pant leg saying, "why" to every answer she gives.  I continue until her answers are abbreviated to "because," and I reply with an tug,  "but,why?"

"Because,"

"Why?"

and finally with all her patience wearing thin, she snaps, "BECAUSE!"

Ok, the long and short of it is that I asked why keys work the way they do, not at first, but later on.  I will go out on a limb here and say that most of the questions get answered through formulas, and this one is no different. 

When building a Key all you do is start to with the note of the key you want to play in, like C for instance.  Then recite the C scale; CDEFGABC.  Knowing the scale, we add the formula 145, (not to be confused with the major chord building formula 135) and we get CFG.  That is it.   If you want to build the Key of A you just say the A scale, pick out the 145 notes and you have ADE. 

The question you should be asking right now is why are F and G chords in the Key of C when you know that F has a B flat, and G has an F sharp in their scales.  Here's why:

As you can see, the F and G chords do not have any sharps or flats in them.  Their scales do, but the chords do not. You can easily pick up their notes with the C scale, because the C scale has no sharps or flats.

The two formulas do more for you then build chords and keys, they show position.  For example; In the key of C, the F note is 4 notes away from the C note, and the G note is 5 notes away from C, or 1 note away from F.  If you think about it in steps, which I think all things guitar should be converted into steps, F is 2 whole, plus 1 half away from C, and G is 2 whole, plus 1 half, plus 1 whole, or just 1 whole step up from F.

Sounds confusing I know, but it's not because in the end, when you have your guitar in hand, you will see the steps and not just read about them.  I picture the steps as 2 +.5 = F, 2 + .5 + 1= G.  When playing you cannot get bogged down with words, so try to see the steps in numbers.

Knowing that the formulas help with finger position, let me break down what notes to play and when to play them. Going back to chord building, the C chord is comprised of CEG.  Finding the notes on the C scale is easy, because you can play the 1st, 3rd, and 5th notes--it looks like this:

This works just as long as your accompaniment stays on C chords, but what if they change to an F?  Bring the key formula 145 back to mind, all you do is pick up the 4th note in the scale (because the 4th is F) and repeat the 135 formula. It looks like this:

What happens if they switch to G?  Again, the key formula shows you where to play.  G is the 5th note in the scale, so quickly move up to the 5th position and play your 135.   It looks like this:

I know I cheated and grabbed the D in the next octave, instead of the D note sitting above the G note nestled on the A string on the 5th fret. I did this because that is how I play it most of the time.  At this point, there are two things you should notice:  one is how the formulas work to give you finger position, the other is the similar pattern all three share .  The 3rd note of the scale is a half step down on the string above (backwards sounding I know, but your 1st string is the high E)  and the 5th note is .5+1 steps away from the 3rd note.  If you play the 1st note with your middle finger and the 3rd with your index and then make the long stretch over with your pinkie to reach the 5th, you can practice this idea easily.  Here they are all together:

I suggest doing this: C,135;  F,135;  G,135 and repeat in different ways. you can get a good slide up and down the neck between the F and G notes.   Do not stay in order, you need to hop about because that is what songs do.  When you feel comfortable remove your hands and practice playing them without the memorized positions. 

On a side note:  I would put a guitar player up against anyone in the game of memory.  You know, the one that starts with all of the poker cards face down and the goal is to get as many matches as you can by remembering where the card you need is located after seeing it turned over for a moment.  Guitarists are just prone to memorize position, it stems from their reliance on chords.  I would go further and say that they can even remember each technical position done in the songs they play without the use of scales, it is just something that they focus on. But when the chords are removed, steps and scales must take their place or all the notes get lost in the shuffle.