Music Theory for Guitar

Please note: This whole section is currently being developed and is not yet complete at this time.

This section tries to explain the thinking behind the way I play the guitar. I am hoping this will help in getting you new ideas in expanding your own playing. Note: This is not a complete explanation of music theory.

Scales

The Major Scale

The W below means "whole step". A whole step means moving up two notes (or two frets), and H means "half step" which means moving up one note (or one fret).

The Major scale consists of 7 notes. To play a C Major scale, let's first look at the notes in the C Major scale, excluding the Octave.
The notes are: C - D - E - F - G - A - B.

Below, we show the 8th note (the Octave) as well. The Octave is the same note as the 1st note, only one octave higher. As we go from C to D, you are playing one whole step - there is one fret between these that we skip. Same goes from D to E, it's one whole step. Next, we go from E to F, and this is only a half step.

After that, we Going from F to G, we play another whole step. Same goes from G to A and A to B, those are also whole steps. Lastly, the B to the Octave C is a half step. So, looking at the following, we see that there are 5 whole steps and 2 half steps in the Major scale:

  1   2   3   4   5   6   7   8
      W - W - H - W - W - W - H
  C   D   E   F   G   A   B   C

As you learn this scale, I recommend you use a backing track or something that will play a C chord continously. Play the scale slowly, note for note. As you play through the scale, pay attention of the sound of each note in relation to the C chord. Now we are in fact talking about Intervals.

Intervals

What are Intervals? Simply put, Intervals are labelled according to their function in a scale. Looking at our chart again, we see that the D note can be viewed as 2nd, the E note is the 3rd, etc.

  1   2   3   4   5   6   7   8
      W - W - H - W - W - W - H
  C   D   E   F   G   A   B   C

I find that it is much more important to know what Interval the note is, than what actual alphabetic name it has. By this, I mean, is it the Major 3rd you are playing? This is also a way of training your ears to be able to identify what a Major 3rd and so on sounds like.

Why is it called a Major 3rd? Well, there scales that have lowered or raised notes. We can also see that there is a note between the C and the D note, and the same goes for the notes between whole steps above. Here are the names of all the Intervals there are:

Interval Name	Number of Half Steps
Perfect Unison	0
Minor 2nd	1
Major 2nd	2
Minor 3rd	3
Major 3rd	4
Perfect 4th	5
Augmented 4th / Diminished 5th	6
Perfect 5th	7
Minor 6th	8
Major 6th	9
Minor 7th	10
Major 7th	11
Perfect Octave	12

This table covers all 12 notes, or all the notes on one string up to the 12 fret.