Even if you don’t compose music, knowing some basic music theory can seriously level up your DJ sets. Understanding rhythm, key, harmony and more helps you make smoother transitions, mix in key, and choose tracks that work well together.

But which pieces of music theory should you be digging into? Where do you start when you want to train your musical brain? Well, we put the call out to our Mixcloud community for the answers. Here are just a few pieces of music theory that you can take with you into your next mix.

Pitch and rhythm

Two of the many things that lie at the heart of anything musical are pitch and rhythm. They help you keep your DJ set in a good flow and energy. You can recognize patterns that can blend together well when you’re picking a track to blend into. If you want to mix two tunes together on your decks, you need to adjust the speed of the track to fit the other. To do this, you adjust the pitch.

Pitch

Simply put, pitch relates to how high or low a sound is and its frequency. Each pitch has a different frequency, which is what makes it sound high or low or somewhere in between. For example, have you ever noticed when you tap a glass in certain areas that the sounds are different? One sound you make might be high-pitched, but a tap in another place might emit a lower sound? This is pitch in full display, with any single part equalling a different frequency. 

Different instruments also give off different types of pitch. A woodwind instrument like an oboe is likely to have high levels. Meanwhile, a string instrument like a double bass is traditionally low in pitch. Meanwhile, guitars and pianos can be played at both high and low pitches. In a DJ set, you can adjust the pitch of tracks at your will. You can use faders on your CDJs to control the speed of the song you’re playing. Thus, creating all kinds of opportunities for your blends.

Rhythm

Meanwhile, rhythm is the pattern of sounds, silences and emphasis that creates a sense of movement, pulse, and groove in a song. It’s the arrangement of notes and rests in time, and it tells you when notes are played, how long they are played, and with what intensity. Rhythm is at play with every song you can think of, and more, but in increasingly different ways. A Techno song, for example, is rhythmically constructed differently to a Rock song. It will have different silences and emphasis on chords, keys and other notes. With an understanding of rhythm, you’ll be able to better find out which tunes work best for you when you’re looking for new music for your set.

Time signatures

In music, a time signature is how the rhythmic pattern of your music is characterised. It’s made up of bars, which are groups of beats. A time signature will indicate how many beats there are to a bar so the 4/4 time signature (widely used in dance music) is made up of 4 beats to a bar, meaning each quarter note gets one beat. Think of The Bee Gees’ classic ‘Stayin’ Alive’ and its pulsing rhythm; each snare counts as a bar with four beats. A bar can have different note durations, as long as the total duration remains four beats. For example, a bar could have one whole note, two half notes, or a half note with two quarter notes, any mixture of half and quarter notes.

Sometimes, tracks will have eight-bar loops. These are sections of music that run eight measures long, sometimes referred to as ‘phrases’. Essentially, these are loops of your main melody. An example of a famous track that runs on an eight-bar loop is Elvis Presley’s ‘Heartbreak Hotel.’ Typically with these, your musical arrangement will change in some way after every eight bars. It could be a new synth, a different snare, hi-hats or a new drum pattern. Ultimately, time signatures help you understand how to count music. That way, you can drop the beat of your next track at the perfect time, get them playing in sync and seamlessly mix from one to the other. 

The circle of fifths

Now you know about pitch, rhythm and bars, let’s get into musical keys. These tell you which sounds go well together and which clash. They’re divided into major and minor keys, which all revolve around 12 musical notes, ranging from A to G and the major and minor versions of these notes. For example, B major will sound different to B minor, and so on. That’s a total of 24 keys that your music can live and develop within.

If you want to get an idea of all major and minor keys and how they work, the circle of fifths is a great guide. It’s a visual wheel showing where all notes in major and minor sit. Major keys are on the outer circle and their minor keys are in the inner circle. Each letter in the circle can be either a chord or a note. The circle of fifths does a great job of assigning musical keys to their accompanying note. So, if you’re a DJ, you’ll have a greater understanding of what can be mixed with what, according to their key. The best part? You don’t have to remember each of these keys; music experts have already laid the groundwork. Which leads us to…

The camelot wheel

Where the circle of fifths visualizes every musical key, the camelot wheel goes a little deeper. It shows you every minor and major chord, with a number and letter combination showing all 24 minor and major keys. From 1A to 12A and 1B to 12B. Like the circle of fifths, it tells you which musical keys sound best together. Once you know what the key of a song you want to play is, refer to the camelot wheel to work out which other keys work with it. Or take it a step further and guide the story your mix tells by shifting from a major to minor key or vice versa. This will make the tracks in your mix mix sing from the same hymnsheet, so to speak!

The wheel was designed specifically for DJs to get to grips with keys and chords. To understand how melodic and harmonic tunes can be blended together effectively. So, this is a great resource to go to if you want to learn. Or, to go back to if you want to sharpen your knowledge. You can use the wheel to inform how you put your mixes together. Or even to organize your playlists by key, without having to spend much time memorizing the circle of fifths.

Harmonic mixing

Once you have a basic understanding of keys, you can apply harmonic mixing to your DJ sets. Harmonic mixing involves making sure that the keys of the tracks you blend are harmonically compatible. In other words, in the exact same key. This allows your mixes between tunes and your overall set to be a lot smoother, because your transitions will have the foundation of being musically aligned with each other. Elements like notes, chords and melodies of each following track will work together. This can apply to whether you specialize in one genre in your sets or prefer an open format.

If you master harmonic mixing, you’re able to really determine the vibe of your mix from a musical and theoretical standpoint. Let’s say you arrange your tunes in your library by key; you have a ready made list of tracks to get into and play. It’s a fairly advanced technique, because you have to be aware of the key of every track you play, which may take some time. Mainly because you’ll have to train your ear to detect different keys. But this can be accomplished using DJ software like Serato, Rekordbox and Virtual DJ. Making use of the circle of fifths and camelot wheel can help paint a picture of where keys lie and how they talk to each other. You can apply both to your learning if you choose to use software to get to grips with harmonic mixing.

Time to get stuck in!

Knowing these five areas gives you a strong foundation for better DJ sets: your transitions become smoother, your sets more musical, and your audience more engaged. Start with song structure and key, and the others become much easier to add on.