What Is Guitar Theory?



What is Guitar Theory?

  • Do you have a hard time learning songs, remembering their parts, and understanding their structures?
  • Are you stuck in a rut trying to compose your own music?
  • Would you like to be able to spontaneously improvise and jam?
  • How many times have you learned something new on the guitar without quite knowing what to do with it?
  • Have you noticed that many of the guitar instructional materials on the market feature lessons that teach you the “what” and “how” but not the “why”?

Without knowing how music works you are going to struggle with everything you do on guitar. Music theory provides you with the knowledge and know-how to bring all the elements of music together so that you can make music work for you and have complete control over what you play.

Music Theory

Generally speaking, music theory is the study of music, its elements, and its workings. It’s the way you analyze, classify, and compose music and the elements of music. In the traditional sense, music theory also relates to the way that music is notated, the way music is performed, and the interrelationship between the two. You could say that music theory is the mechanics of music both written and played.

Guitar Theory

While music theory pertains to music in general, guitar theory pertains to the guitar specifically. Typically, this includes only those aspects of music that enable guitarists to find their way around the fretboard, play music, and compose. You won’t get far on guitar without learning chord shapes, scale patterns, chord progressions, note positions, and intervals. You won’t accomplish much if you don’t understand keys, modes, harmony, chord relationships, and scale applications to some degree. Without some understanding of rhythm and without developing technique your playing will never take shape. By learning guitar theory, you equip yourself to play songs, compose your own music, and improvise.

Guitar Scale Theory

In music, a scale is a series of notes played in ascending and descending fashion. Scales are used to play melodies, riffs, solos, and bass lines. Scale notes make patterns on the fretboard, which guitarists finger and pick position to position. Successfully using scales requires more than simply memorizing their patterns, and this is where music theory, or in this case, scale theory, comes into play. Have you ever seen a guitarist learn the basic chord changes to a piece of music and then instantly begin improvising using scales? A skilled guitarist knows how scales relate to chords and can combine the two on-the-fly. Different types of scales produce different types of sounds from major to minor, from pop to blues. A versatile guitarist understands how scale modes work and knows what’s appropriate in any situation.

Guitar pentatonic pattern one

Pentatonic scale pattern one, as shown here, is perhaps the most widely known and used scale pattern on guitar. It can produce a major, minor, or blues sound depending on how it’s applied.


Guitar Chord Theory

In music, a chord is a group of notes that ring together in harmony. One of the first things that beginning guitarists learn is how to finger a basic chord shape and strum across a group of strings. Chords are usually at the base of every song and help to establish the tonality of a piece of music.

Chord theory is the study of how chords are built and how different chords relate to one another. This includes knowing basic chord structure, the difference between major and minor, the use of added chord tones and extensions, and the concept of voice leading. Guitarists make use of fragmented chord shapes, chord inversions, and chord voicings, and it all stems from their knowledge of chord construction. While simply memorizing chord fingerings is a suitable way to initially get started with playing guitar, getting to know chord theory is how you develop a working knowledge of music and become most proficient as a player. One of the best ways to learn how chords are formed on the fretboard is to study the guitar and chord-specific CAGED system.

Chord theory also involves the study of chord progressions, which are the ways chords are put together to form a series of chord changes. As chords change they determine the music’s movement and a song’s structure. Composing a chord progression requires you to understand relationships between chords and concepts involving the way chords lead to and pass from one another. How is it that some guitar players seem to know what’s coming next in a song even when it’s their first time through it? Because chord progressions typically follow predictable patterns with their movements based on familiar scale structures and simple number systems. You get to know guitar chord progressions and playing by numbers by working with the chords produced by the major scale and its seven scale degrees.


Get Guitar Theory Instruction in the Member Area

Hopefully, you now see that studying theory will uncover the mysteries of music and help you more quickly develop your skills as a guitarist, songwriter, improviser, and composer. Your journey begins in the GMT Members area, where you will find video lessons pertaining to scales, chords, progressions, modes, and more. Aside from learning these components of music individually, you learn how they fit together to make music. Furthermore, everything is taught from a guitar player’s perspective by focusing on the fretboard and relating all concepts to familiar songs.


About Desi Serna

Desi Serna guitar music theoryHailed as a “music-theory expert” by Rolling Stone magazine, guitarist Desi Serna is a music instructor and author who has written several books on guitar including Fretboard Theory, Fretboard Theory Volume II, Guitar Theory For Dummies, Guitar Rhythm and Technique For Dummies, and How To Teach Guitar and Start Your Own Music Instruction Business. He is known for his practical, hands-on approach to music teaching, with a focus on the guitar fretboard and emphasis on popular songs. Desi honed his craft through decades of teaching, performing, and publishing. He lives in the Nashville, Tennessee area, produces all the instruction featured in the GMT Members area, and is online everyday connecting with his subscribers and giving guitar players personalized training and support.

Beginner Guitar Theory

I do not recommend that beginner guitarists study music theory. If you’re just getting started with guitar, then focus on learning the basics of playing. For more information, please visit my beginner guitar page which features free guitar lessons for newbies.

Read More About Related Guitar Theory:

What Scales To Learn

How to Learn Chords On the Fretboard

How to Play Guitar Chord Progressions

What Are Scale Modes?

Learning the Guitar Fretboard

What Is Fretboard Theory?