Music is a type of math. Or rather, it’s the opposite on the boredom scale, but having a mathematical approach is a useful way to understand what you’re doing as a DJ. Have you heard of the circle of fifths? It’s the way that song keys are classified. And you can use it to your advantage when selecting tracks by key. Get into the flow of learning to DJ by checking out a few basic principles behind the effect of sound on the human body. 

Step to the right

Our biology controls us. That’s why we can predict that when you raise or lower the key between one track and another in your set by a fifth (seven piano semitones), a ‘brightening’ or ‘darkening’ effect happens. It’s true. According to the music theory that we all respond to unconsciously, going from a track in C Major up a fifth to a track in G Major has a more uplifting effect than going down two ‘steps’ to a track in Bb. Here’s the circle of fifths diagram that helps explain it better. Step to the right and you raise the energy. To the left and you darken it. That’s biology, folks. 

Body tempo

Your heart rate is the main reason that we love music at 120bpm and find 250bpm a little fast. A normal resting heart rate is around 60-80pm. Once you start dancing, you raise that up to 120-150. Higher than this range and your body starts to feel overwhelmed. A whole lot of music theory is structured around this principle. Nothing mysterious, just common sense and basic workout science. 

Frequency magic

You know all that stuff about 432Hz having mysterious healing power? Mostly baloney, and most evidence of sound frequencies being healing is underproven. But we all know what happens when we cut the lows! Be aware that low frequencies allow your crowd to catch their breath. A dip in the mid frequencies allows them to talk more easily, while boosting them emphasizes the melody and harmony of the track. And high frequencies are best used to remove the excitement so that you can drop it back in. One, two, three, bingo!

You obviously don’t need a biology degree to DJ. It does help seeing yourself as more than just a playback machine, and having an in-depth sound knowledge will raise your chances of working on bigger and more complex rigs. Don’t be intimidated by the science. Be fascinated by it. Learning psychoacoustics is a good place to start. Use these principles in your mix by signing up for a DJ course by DJ Courses Online. 

John Bartmann is a music producer and DJ.