Music theory is the language of music, and like learning a second language, it can be dull and seem pointless. However, when you do master it, become fluent in this second, symbolic language, you will find yourself able to musically converse in a way you never could before.
When are we going to use this theory? Especially for singers, theory can seem tedious. While instrumentalists almost always use notated music, a vast majority of voice students, including mine, can successfully master a song without looking at any papers at all simply by listening to a song repeatedly. The question is, what happens if you have never heard the song, and don’t have time to listen to it? I worked professionally in a beautiful church in Newark, New Jersey, whose pastor was an enthusiastic Italian-American whose tastes ran in a very traditional bent. It was not uncommon for the dusty black phone to ring while the morning light was still struggling through the stained-glass, the pastor requesting a Latin Mass to be sung, one that neither myself nor the organist knew. How does one, with their eyes still half-glued shut with sleep, sing an entire mass they never heard? Music theory! Because I understood not only how to read the notations, but also the way in which the notes interacted with each other melodically and harmonically, I was not only able to sing the music well, but was also able to add some harmonies if there was a chance to.
What is it exactly that I am trying to tell you? To be a musician who doesn’t understand how theory works is like being a writer who doesn’t understand how grammar functions, or a painter who doesn’t understand how colors mingle. You can still be successful, and there are many musicians who have had careers without any kind training; but they are rare, and every single one of them at least has a basic knowledge of music’s underlying structure. Much more common are musicians like you, or I, or Johann Sebastian Bach, or Johnny Greenwood, whose art is only enhanced through understanding the inner gears.
Allow me to wax poetic. Going beyond being able to read the black dots on the page, you begin to understand the intricate ways the notes weave together, the patterns and textures that emerge, the vast aural tapestry of sonic undertones that shifts with the modulating function of each note within each chord. There is a practical application to understanding music theory as a professional musician, of course, from the ringer at a church who needs to sing a 12th century chant at the drop of a hat, or the studio musician who plays with a new band every day. It is the language that professional musicians communicate in, the way we make ourselves understood to others, even through the centuries. It is knowledge that helps us make changes on the fly and allows us to go beyond the page. More than that, though, it is the gateway through which you can better understand music, you can enhance your practice time and your performance, and it is a key that will allow you to move from the little black dots on the page towards the creation of true art.