According to wikipedia.org, music theory is the name for a branch of study that includes many different methods for analyzing, classifying, and composing music and the elements of music. Narrowly it may be defined as the description in words of elements of music, and the interrelationship between the notation of music and performance practice. Basically, theory is the study of music, how it’s played and how everything fits together.
Theory is Necessary
Have you ever learned something new on the guitar but had no idea what to do with it? Many guitarists suffer from this ailment and most instructional materials do little to remedy the problem. You can buy a chord or scale book at your local music store and learn some new shapes and patterns, but rarely do these books explain what these components actually do or how they ought to be applied. Without knowledge of how something functions it’s pretty much useless. This is why theory is necessary.
Theory Offers Explanations
Theory will explain what something is and does. For example, a new chord shape might be seen as an extension of a common barre chord. Wherever you may play the barre chord the new shape can be substituted for a new sound. A scale pattern might fit together with a specific chord progression. Each time you play this progression the scale tones can be used to add melody and harmony. Certain combinations of chords will effect a songs overall emotional feel. Choose the right combination in order to successfully convey your song’s meaning.
Scales, Chords, Progressions and More
Music can be approached and studied from many different angles. You can study notation, technique, rhythms, scales, chord construction and so on. While all musical topics are interesting and have their benefits, scales, chords and progressions top the list of must-knows. All guitarists, beginner through advanced, strum chords, follow progressions, and play melodies, riffs, solos and bass lines with scales.
Chord theory consists of how chords are built. Chords are built from scales. Scale degrees, or intervals, are combined to make major and minor chords (see Fretboard Theory Chapter 6 Building Chords). The notes of these chords are scattered throughout a pattern that covers the whole fretboard. Break this pattern up into five pieces and something familiar emerges. One position resembles an open C chord shape, the next an open A chord shape, followed by G, E and D. This is the so-called “CAGED” system which teaches you how to play different shapes and voicings on the guitar (see Fretboard Theory Chapter 3 CAGED Template Chord System and CAGED Template Chord System DVD). Additional theory will teach you how chords become more complex and interesting sounding when more scale tones are added like fourths, sixths, sevens and ninths (see Fretboard Theory Chapter 10 Chord Extensions).
Scale theory consists of how scales are played and how they’re applied to chords and progressions. The major scale is used to play melodies, riffs, leads, and bass lines (see Fretboard Theory Chapter 5 Major Scale). When applying this scale, it’s critical to combine it with chords and progressions that are derived from the same scale. Otherwise you’ll sound out of key (see Fretboard Theory Chapter 7 Applying Scales). Depending on the progression, the major scale can sound happy, sad, jazzy, exotic or strange (see Fretboard Theory Chapter 8 Modes). The pentatonic scale, which is really just a simplified major scale, is easier to use and apply. Rather than take the whole progression into consideration, as is necessary when applying the complete major scale, the pentatonic needs only correspond to the root chord (see Fretboard Theory Chapter 2 Pentatonic Scale and Getting Started with the Pentatonic Scale DVD).
Chord progressions are based on the major scale. Scale degrees, or intervals, are combined to make major and minor chords. When chords are built for each scale degree the following sequence emerges:
7. minor flat five (a.k.a. half diminished chord)
Sometimes referred to as the “Nashville Number System,” this sequence remains the same regardless of key. Guitarists translate it into movable patterns on the fretboard. This allows guitar players to visualize keys as easily as they view barre chords or scale patterns. The ability to identify keys helps to chart progressions, apply scales, play by ear, compose and more (see Fretboard Theory Chapter 6 Building Chords and Progressions).
So you can see how studying music theory will uncover the mysteries of playing guitar. When you understand how the blocks fit together, you’re free to build on your own. Also, knowing what’s important will prevent you from wasting time on useless things. For more information about theory specific to guitar, see Fretboard Theory. Subscribe to the free 25 page preview and also receive bonus details and free tab!