What is Music Theory, and why does it matter?

Updated: Jan 27, 2020

Music theory, at its core, asks two simple questions: why does music sound the way it does and what causes it to sound that way? Music theory studies notes, chords, harmonies, harmonic progressions, rhythm, form, and even human cognition and perception in order to gain a better understanding of music. Now, it is true that when musicians learn that I am a professor of music theory, they often tell me how hard their music theory classes were in college. And it’s true that many of the concepts covered in an advanced music theory class are hard and sometimes complicated. (If you’re on Twitter, I highly recommend checking out @darkmusictheory, which among other comments about the study of music theory, retweets people’s frustrations about their study of music theory.) But, it’s also true that a basic, working knowledge of even the most simple music theory concepts (even if you don’t read music) can be an invaluable skill that can enhance your experience of music. Here are three ways that music theory can make your next listening experience more rewarding.

Number One: Form and Function

Music composed in the tradition of Western art music tends to follow certain formal expectations. Despite this, there are numerous ways a piece of music can unfold with slight variations on established formal norms. But in general, music in this tradition tends to adhere to a simple axiom: start with something, move on to something different, and then return to the original something before the end. This is, admittedly, an oversimplification, but keeping this simple concept in mind allows for a richer experience of the music, inviting all kinds of interesting questions to emerge. When did the original material come back? Was it exactly the same? What changes did the composer make? How is the middle something different from the first something? Is it faster, louder, slower, or softer?

Believe it or not, this beginning, middle, end paradigm is actually at the heart of an important music theory concept known as formal function. Music that happens in the beginning tends to have certain features, and so too does the middle music and the end music. But what if a composer played with this idea? Take the opening of Frederic Chopin’s Nocturne No. 10 in A-flat Major. The piece begins with a familiar harmonic progression, an A-flat Major chord, moving to a D-flat Major chord, eventually settling back on A-flat Major. This progression is familiar to many people as the “Amen” cadence sung at the very end of many Christian hymns (and heard here as the final “hallelujah” from the “Hallelujah Chorus” in Handel’s Messiah). What does it mean, then, when Chopin begins the nocturne with music that functions like the end of a piece? Perhaps it is an invitation from the very beginning of the piece to think about our past, or that the piece itself is somehow a part of Chopin’s past. Regardless of the specific meaning, this kind of observation enriches the listening experience.

Number Two: Major and Minor Modes

One of the very first things I teach someone who has never studied music theory before is the difference between major and minor. Tonal music, the music that makes up the vast majority of all the music you hear every day, is usually in a major mode or a minor mode and the difference between them can often have profound effects on the music. Most people associate major music with happy emotions and minor music with sad emotions, and those pairings are rightly justified. Funeral marches, for example, are almost always in minor, while the tune “Happy Birthday” is in major. But here too, there is room for interesting play. Though not entirely in a minor key, the opening of Pharrell Williams’s “Happy” is an E Minor chord, and this chord is heard underneath every verse of the song. The song, which is unequivocally “happy,” uses a minor chord for about half of the song, calling into question the exclusive power of major to portray happiness. In fact, much of the pop/rock music you listen to everyday is in minor, but the music is anything but sad. Europe’s “The Final Countdown,” a popular tune during the final few minutes of play at sporting events, is entirely in a minor key and nobody would characterize this song as sad.

Number Three: Meter

When most people think of music theory, if anything comes to mind, it’s often complex theories relating exclusively to how notes and harmonies work together in music. And while that’s certainly true, music theory must also account for the one thing that sets music apart from other art forms: time. Music requires time in order to be experienced, so just as important as what is heard is when it is heard. Common-practice music, music composed in a Western musical tradition from around 1600 through the late 1800s, explores time in a variety of different ways, but we can think of this music in two large categories; music in groups of two and music in groups of three. The first category is referred to as simple meters (the word meter simply referring to the way rhythm is organized in each measure of music), and for every main beat you hear in the music, there are two smaller, subdivided beats. The march Stars and Stripes Forever is a piece in a simple meter, and you can hear this as a somewhat rigid, perhaps even angular division of the beat.

The latter category is compound meters, and they allow three smaller, subdivided beats. Compound meters often sound like they are lilting, less rigid, and more rounded. The song “Beim Absch