by Scott Zimmerman

If you have played guitar for any amount of time, you might be asking yourself this question or just wondering what guitar theory means. That’s good. Clearly, you enjoy playing the guitar and want to know more. Let’s say you love to play guitar, enjoy learning new songs, making music with your friends, and just playing for pure enjoyment. Then, no, absolutely not!, you don’t need to learn guitar theory.

We know there are many necessary things we “must” do in life, so don’t ruin your enjoyment of a hobby by putting a “should” in front of it. However, let’s say you enjoy the guitar so much that you want to know more about it, then yes, you absolutely “need” to learn guitar theory. So, when you read “mastery of the guitar” in the following article, think LOVE that instrument, can’t get enough of it, what else can I learn about it!

Oh, and by the way, no one can truly claim to be a complete master of the guitar. Yes, there are many who have mastered certain aspects and styles of playing, but the possibilities of the guitar are too vast for anyone to claim complete mastery. We all are journeymen on the quest for our own unique mastery of the instrument. Ok – let’s jump in!

Why should I learn guitar theory?

Mastery of the guitar includes disciplines such as performance, technique, ear-training, music reading, music theory, and guitar theory. Therefore, in order to master the guitar, it is necessary to learn guitar theory.

What is guitar theory?

Guitar theory is a body of principles offered to explain how the guitar musically functions. This includes, but is not limited to: identifying notes on the fretboard, identifying intervals, constructing scales, understanding key signatures, building chords, identifying chord progressions, etc.

Is guitar theory different from music theory?

Music theory may be defined as a body of principals offered to explain how music functions; whereas, guitar theory is a body of principles offered to explain how the guitar musically functions. In other words, the goal of guitar theory is to understand how the guitar musically functions within the context of music theory. It is a study which uses the guitar as the point of reference to understand how music functions within the context of guitar playing.

Why do I need to learn guitar theory?

Let’s answer this question by way of an analogy using car ownership. The end goal of owning a car is to provide transportation to accomplish some type of task. The car is the object used to complete the task. If the car can not be used, or used effectively, the end task is either not accomplished or accomplished with poor results, i.e. if the car stops working you can not get your groceries. However, if there is an understanding of how the car works, e.g. a car needs gas, the car is out of gas; therefore, put gas in the tank, etc., then the problem can be fixed and the task for which the car was intended can be accomplished. 

Similarly, the end goal of playing the guitar is to play music. If there is a lack of understanding as to how the guitar does this, the end goal cannot be accomplished or it is poorly accomplished. For example, let’s say you are playing a song that you would like to sing along with, but you are having trouble singing the notes because they are out of your vocal range. Understanding how to transpose music to a different key will solve this problem- that is guitar theory.

Is it wrong to play the guitar and not understand it theoretically? No, understanding how the guitar musically functions is not a necessity for enjoying the experience of playing music. However, many guitar players want to know more about how it musically functions, and this is where the desire to learn guitar theory begins.

Is sight reading music the same as guitar theory?

No, they have different end goals. The end goal of reading music is to decode a written symbol into sound measured in time. This is a separate discipline and requires its own study to master. To use another analogy, reading music is similar to learning to read words; whereas, music theory is similar to learning the rules of grammar. However, learning note names on the guitar and where they are located on the musical staff is prerequisite for learning guitar theory.

What does a guitar theory curriculum look like?

The guitar can be viewed from two distinct perspectives based on the desired musical end. First, it is a melodic instrument. (A melody is created when successive notes are sounded continuously over time, e.g. singing.) Melodies consist of composed melodies as well as improvised solos. Secondly, the guitar is an harmonic instrument. (Harmony is created when two or more notes are sounded together or closely together, e.g. chords.) 

Melody and harmony are the horizontal and vertical dimensions of sound. Some instruments are only melodic instruments, e.g. trumpet, saxophone, voice, etc.; whereas, the guitar is both a melodic and harmonic instrument. Therefore, there are two branches, so to speak, to the study of guitar theory, i.e. melody and harmony. Each branch, however, is created out of the basic “root” material of the note and interval. (Intervals are the distance between two notes measured in half-steps.) Therefore, the study of guitar theory begins with the knowledge of individual notes and progresses to intervals. 

At this point, we reach the separate branches of melody and harmony. (Generally, the branch of melody is taken up first, but not necessarily.) It is shown how different patterns of intervals combine to make what is called a scale. These scales are grouped into keys or modes and labeled as such, e.g. F major scale, D minor scale, F Lydian (mode), etc. Scales are used to create melodies, which then are grouped into larger concepts of phrasing and finally in to musical forms, e.g. A-B-A form, Verse/Chorus Form, etc.

The harmonic branch of knowledge will show how the use of two or more intervals creates the vertical dimension of sound called harmony. Each harmonic interval combination is identified and labeled, e.g. minor second, major second, perfect fourth, etc. Next, it is shown how different combinations of intervals create chords, e.g. F major, G7, A augmented, etc., and how chords function together to create larger structures of chord progressions that lead to larger formal structures, e.g. verse, chorus, A section, bridge, etc.

What are some practical applications for guitar theory?

There are many, let us mention just a few:

  1. As mentioned above, learning transposition is very practical if you are a singer and a player. It will allow you to sing the song in the natural range of your voice.
  1. Learning how chords are constructed and where the “shapes” of these chords are located on the guitar will allow you to substitute chords and make your playing more interesting. You won’t need to “look up” how to play a chord. You will know how to build it yourself.
  1. Learning how scales are constructed and developing an “ear” for the sound of these different scales is very good ear training and useful for improvisation.

Can I teach myself guitar theory?

Yes, I think you can, if you are patient and work systematically. What does that mean? Simply put, work towards mastery of information before moving on to the next concept. Remember, theory is similar to math in its method. It builds from the smaller to the larger by using smaller bits of knowledge to understand larger concepts. Spend time on each concept and test your knowledge before moving on. Try to apply as best you can the knowledge you are learning to the guitar, by playing examples or creating exercises for yourself. Also, consider at certain points along the learning curve, to reach out to a guide to help answer any specific questions you have while you are teaching yourself.

About the author 

Scott Zimmerman

Scott Zimmerman is a professional music instructor with over twenty years of guitar performance and teaching experience. Scott holds a Masters Degree in Music Education from Peabody Conservatory.