Introduction

Theoretical knowledge about music has two purposes:

1. It is a language common among all musicians.
2. It is a means to better understand, interpret, and compose music.

Musicians need to communicate with one another, especially during rehearsals. Without the technical language of music theory and notation, it would be difficult to describe a specific musical problem that needs to be fixed, or to orient oneself in a particular spot at the request of the director. But music theory is more than just the capacity to read music or communicate to other musicians through musical symbols, it is a means to significantly deepen one’s understanding of the musical material itself.

Music theory unlocks many of the secrets of music: why a particular harmony sounds unique, why a chord progression moves us emotionally, why a rhythmic passage physically excites us, etc. If we want to understand these mysteries, we need to analyze music from a theoretical perspective.

For those who wish to perform, theory is an indispensable guide to interpretation. How should one phrase this excerpt by Mozart? How should one interpret these dynamic markings in Beethoven? How should one approach teaching a choral anthem to a high school choir? These are important questions which every working musician will face on a daily basis. Music theory plays an essential role in this process of music making.

To write music, composers need to understand everything about the mechanics of notation and theoretical concepts. Even though composers don’t necessarily follow the traditional rules laid out in Theory I and Theory II, they must still be keenly aware of these rules and how they influence compositional decisions among the various styles of music throughout history.