What is Music Theory and Why Do We Need It?

Music theory. Often neglected. Sometimes taken too seriously. These rules have us as musicians questioning our musical aptitude, and this human-created structure can hold us back from creating and playing the music we envision. But when taken as a guide as opposed to a strict rulebook, and at the same time giving it the respect it deserves, music theory can be a wonderful utility for any musician’s back pocket. In this article we’re going to discuss music theory and why we need it. 

As we start learning any instrument - piano, flute, voice - we tend to separate ‘theory’ from music. Similarly to other skills, we learn the “by the book” way of accomplishing a task in parallel to actually building, using, and experimenting with the task at hand. Take language as a metaphor. We can speak, understand, read, and write a wide range of language. From a simple text message, to an intricate fantasy novel, to a detailed job interview, we use various sorts of language to accomplish various sorts of tasks. 

But how often do we refer back to the rules to construct and consume language? Rarely to never, I’d say. At some point, we all learned the basic rules of a language while at the same time using the language. It is natural and preferred to stop referencing the rules and lean on our experience to read, write, and speak. Music theory undergoes a similar process. 

We are usually taught the curriculum away from our instrument. In doing so, we understand most concepts within the moment of study. Nonetheless, time passes, musical experience outweighs theory study, and the result? We become a musician (an English speaker for the metaphor) who is very disconnected from the rules and understandings that make music (the rules of the English language). 

Think about this though - how fluent are those individuals who know the language rules and have a plethora of experience? Professional writers and speakers know all aspects of their craft and their work shows it. I’m not saying you need to understand the rules perfectly to pair with your experience. Rather, putting slightly more emphasis on theory will broadly elevate your musical capabilities. 

So, what is music theory anyway? 

Music theory can be challenging to define. It is essentially a human-created system of understanding and organizing the world of music. Over time, music enthusiasts, educators, and scholars have collectively developed this system we know today. We will define music theory as a comprehensive system of notation and standards that serve as the foundation for explaining the intricacies of music and the art of listening. 

Theory allows us to decipher what is happening within a piece of Western music, providing a roadmap to appreciate its beauty and complexity. It is important to note we are discussing Western music which encompasses genres like Classical, Pop, Jazz, Rock, and any music that relies on our system of theory. These preferences can vary across different cultures and musical traditions. For instance, Indian music employs separate scales and rhythmic patterns, as well as quarter-tones, which are notes between notes.

Now that we’ve defined music theory, we can dive deeper into its components. At a basic level, we can split them into the following categories:

Scales

Scales are the building blocks of music. They define how a piece of music will sound and what notes are to be played. To take us back to our language analogy, scales are like an alphabet. Scales are to music as the alphabet is to English. The alphabet contains the most basic elements in language - letters. A scale contains the most basic elements of music - notes. 

A scale is a set of eight ascending notes that begin and end on the same note an octave away from each other. This means there are seven unique notes with one repeated note at the end. An octave is the word used to describe the distance between two notes with the same letter name. This is the main type of scale in Western music. There are several others with varying note quantities (five-note scales, seven-note scales, etc.) and with assorted intervals. We don’t need to worry about those for now.

Let’s look at the simplest scale, C Major. C Major is written as C D E F G A B C. The scale starts on C and ascends in pitch until it hits C again. Here’s what C Major looks like on a piano 

There are 12 major scales and 12 minor scales (similar to having 24 different alphabets). A single piece of music can be based on one or many scales. As you can guess, this gets complex. For now, just understand that pieces are played using the notes of a particular scale. That being said, when we use these scales we can play one note at a time or more than one note at a time. This brings us to our next music theory component - Chords.

Chords

A chord is any harmonic set of pitches consisting of multiple notes that are sounded simultaneously. Simply put, chords are notes played at the same time. Chords are made up of notes in the scale. Our English analogy associates chords with words. The alphabet is a scale.  Letters are notes in a scale. Words are chords. The simplest chords are made up of three notes from a scale. These chords are called triads and they are formed by playing every other note from the one you started on.

Looking at our C Major scale again:

C D E F G A B C

If we want to play a triad that starts on C, then we’d play C-E-G. 

Notice we skipped D, and F. We can do this similarly with every note in the scale. The D triad is D-F-A, E is E-G-B, and so on. Note that each of these triads will sound different in tone and feeling because the intervals between notes change as we move through the scale. 

These chords can also have notes added above, below, and between the three notes. This can create tension and pull toward another chord, which brings us to our third music theory component - Harmonic Progressions.

Harmonic Progressions

As chords move, some of them contain notes that clash with the central tone of the song, creating tension. This tension rises as the notes conflict more and more, prompting a desire for resolution. Musicians may choose to highlight or prolong chords with tension, making the resolution more dramatic. This deliberate approach aims to capture the listener's attention and create a more engaging musical experience.

Now we have a basic understanding of the components that make up music theory. So how is this useful? Why would we want to know these details and further our understanding of them?

There are several reasons why. 

Sight-reading

Sight-reading is an essential skill in musical interpretation, emphasizing recognizing shape and feel rather than individual notes. Proficiency in music theory enables us to anticipate chord progressions, much akin to understanding the direction of sentences while reading. This level of familiarity transforms the act of reading music into a coherent process, similar to comprehending words and sentences, rather than decoding individual notes on a page. The mastery of chords and notes through memorization and repetition facilitates the internalization of music.

Listening

Listening to music, whether recreational or educational, is drastically improved with a nuanced understanding of music theory. We’ve all been at the point where we’re listening to a song and wondering what the heck we’re hearing. What notes? What chords? Familiarity with the typical movement of music enables us to listen to a chord progression or melody and intuitively grasp the notes being played. Even without perfect pitch, we can begin to write down or play what we are hearing. 

Composition

It is possible to compose music without formal music theory knowledge. However, an awareness of theory expedites the compositional process. Even this is a massive understatement. 

Let’s consider our language metaphor. We can technically write a sentence without knowing the rules of English, and only knowing the words of the language. Perhaps we’d come up with quite the experimental, artistic sentence. Conversely, if we knew the language rules beforehand we’d be able to write a sentence in our sleep. Using this basis, we can have as much fun pulling away or pushing into the language rules as much as we want. 

An extensive understanding of theory drives creativity, potentially allowing composers to deviate from established rules while still benefitting from a faster and more informed composition process. It’s the classic case of first understanding the rules and then breaking them.

Memorization

If you’ve practiced music to any extent then you know that memorization is a big aspect of musicianship. When we learn a classical piece, a pop song, or a soundtrack excerpt, we want to take it with us wherever we go. That way we can play it anytime and anywhere. A broad and general understanding of theory - scales, chords, harmonic progression - simplifies memorization because we can more easily recreate and recall the piece. 

For example, let’s say we’ve memorized a piece. While practicing we’ve forgotten a note. Instead of looking at the music we can use theory to recall the key signature (which scale we are using), the chord, the progression, and the overall feel of the music to make an educated guess on what note is next. The concept of seeing and hearing bigger units rather than each note can make it far easier to memorize.

Communication

Finally, music theory serves as a communicative tool, enabling clear and effective expression within the musical community. A shared understanding of terms and their meanings allows us to precisely communicate, collaborate, and convey our musical ideas with accuracy.

Bottom Line

Music theory is not just an academic pursuit but a fundamental tool for musicians, composers, and music enthusiasts alike. It serves as a bridge between the creative expression of music and the intellectual understanding of its inner workings. By delving into the world of music theory, we embark on a journey that enhances our appreciation for the art form and equips us with the tools to create, interpret, and enjoy music at a deeper level. Whether you're a seasoned musician or a curious novice, understanding music theory is an invaluable asset on your musical path.