Music theory in brief

To get on the fast track for learning some music theory, learn 3 things. 1) the notes of music, in order, 2) the format for the Major scale, 3) the format for Major & minor chords.

1) Learn the 12 notes of music up & down. They’re the same for any instrument, & they’re alphabetical (A thru G), with some flats or sharps in between (the / marks represent different names for the same note. A# = Bb. Also, # = "sharp", b = "flat"):

A, A#/Bb, B, C, C#/Db, D, D#/Eb, E, F, F#/Gb, G, G#/Ab

(Notice: B to C and E to F are the only intervals where there is no sharp or flat between them.)

2) Using the notes above, learn the notes of some key Major scales (8 notes long). The form of a Major scale is:

1 - W - 2 - W - 3 - h - 4 - W - 5 - W - 6 - W - 7 - h - 8/1

W = Whole step = up 2 notes from where you are
h = Half step = up 1 note

So, if you want to make the C Major scale, you would start on a C (1), then go up a Whole step (2 notes) from there, which would be a D (2). The whole scale would therefore go:

C D E F G A B C

Do this for C, G, D, A, E, F, & do your best to memorize them forward & back, inside & out. There are 6 other keys as well, but these will get you started.

3) Learn the notes of the Major & minor chords for each of those keys. The form of a Major chord is: 1 3 5, meaning the first, the third, & the fifth notes of the Major scale form the Major chord. For example, a C Major chord is composed of the notes C, E, & G. The minor chord has only 1 difference – the middle note (3) from the Major chord is 1 fret lower. So the form is: 1 b3 5 (b3 = flat 3). The “flat” 3, or “ b3 ” gives the minor chord its characteristic sad/dark sound. In the case of C minor, the notes would be C, E b (E flat), & G.

Once you memorize the notes for the Major & minor chords for C, G, D, A, E, & F, along with their Major scales, you’ll have a strong arsenal of knowledge.

This may seem confusing at first, but knowing this info will prove invaluable when you can put all the pieces together in your mind. Music can just pour forth from you with little or no thought. Obviously, there's more to it than this, but this is a good start. Checkout the above mentioned resources for a much deeper & rewarding experience in guitar instruction. Have fun!