🎵 Music Theory for DJs
How understanding the 'laws' of music can transform your DJ sets.
While attending the Mobile Entertainment Expo in Las Vegas in February 2025, I sat in on a unique presentation by DJ JeffyJ (aka Jeff). It was a fascinating and educational talk that I think every wedding professional needs to hear.
Mixing music is more than playing the biggest hits. So much more should go into a music set.
So, I reached out to Jeff and asked if he would like to share his presentation with you, and he said “YES”!
Music Theory for DJs
Written by: Jeff Heidelberg
Music has rules—and no, it’s not here to kill your vibe.
“I fought the law and the law won”. This song by The Clash blared through my CD player and defined my teenage years. Yes, I didn’t break any laws in my younger days, but I was one to rebel against the rules of my parents and anyone who couldn’t arrest me. So imagine the surprise I felt when I learned that music has laws.
How dare “the man” try to control me and my creative process! I’m a high school punk rock drummer, I don’t care what Beethoven or some dead composer says, I let the music come from my soul, not my brain or a rule book.
My AP Music Theory teacher in high school helped reshape this stubborn idea I had. The laws of music are similar to the laws of physics; they don’t restrict things, they help explain things. Music Theory can shed light on why songs make us feel the way we feel. Why does Cher’s “Believe” make us feel euphoric? Why do Christmas songs have such a nostalgic, cozy feel?
It’s time for us DJs to implement these laws into our sets and take our understanding of music to a new level. Yes, the average guest will not be paying attention to the key of the song, but having some understanding of the laws of music will make your sets that much better. Sit down, class is in session.
Phrases and Form
Structure creates flow - and flow controls the dance floor.
Songs have structure to them. We know them as intros, verses, pre-choruses, choruses, breaks, bridges, and outros, to name a few. Most of these elements are broken up into a series of 4.
4 beats in a measure, aka a bar
8 bars in a chorus
16 bars in a verse
This is normally covered when one begins their journey in beat matching, but to take it a step further, we can use these structures to control the energy of the room and our crowd. Want to avoid a lull? Mix your next song's pre-chorus over the last chorus. Want to slap the crowd with energy? Drop a chorus into another chorus.
Timbre
Timbre is how music feels—use it to guide your set’s mood.
No, I didn’t misspell the Pitbull and Kesha hit. Timbre describes the characteristics of a sound. For example:
Gritty: Beastie Boys, AC/DC
Energetic: Avicii’s “Levels”, Usher’s “Yeah”
Smooth: Luther Vandross, Adele
Using these characteristics can help us decide what songs we should play next so the overall feel of the set carries through.
I often use the analogy of playing Uno when I describe programming a DJ set. If you throw down a red 5, I need to throw down something similar to keep play moving. Programming our sets based on the feeling and characteristics of songs can help us establish a groove and pocket. When it’s time for us to exit and switch it up, we can then choose a song that heads in a new direction to give the feeling of a new chapter in our set
Keys
Mixing in key makes your set feel magical - even if no one knows why.
This one can be a doozy, but it is incredibly worth it. In music, there are scales, a sequence of notes that have a harmonic relationship to them. Major scales sound happy, and minor scales can sound sad, but of course isn’t always the case. Fun fact: most music we play is in a minor key.
Some scales use most of the same notes as other scales, which increases the chance of the 2 songs being harmonically compatible and sounding good mixed into each other.
You may notice in your DJ software that there is a number and a letter next to the song (e.g., 4A, 12B). This system, called the Camelot Wheel, shows us what songs are likely to sound pleasing when mixed together. The rule for the Camelot Wheel is that you can move up or down a number or switch from an A to a B and vice versa. You can mix from:
4A → 5A or 3A (number change)
4A → 4B (letter change)
I believe this rule shouldn’t define your entire mixing style and your set, but it can elevate the set in ways that are indescribable to your audience. Think of the first time you heard a mashup and your brain lit up like the 4th of July, that’s the beauty of key mixing.
Tools of The Trade
Music theory doesn’t limit creativity—it unlocks it.
The entire world of music theory is a collection of tools we can use to create the art we want to create. Of course, you can survive without them, but it will be more difficult.
Dream first. Then plan.
I like to imagine how I want the night to feel—highs, lows, cheeky moments—and then build the set with the tools that theory gives me.
Just one of these ideas can dramatically change how you DJ and program your sets.
The law will always win; don’t fight it.
About the Author:
Jeff has been a musician for most of his life, specializing in piano and percussion. He fell in love with DJing about 12 years ago and has been a professional DJ for around 10 years. During this time, he has performed for various local and national companies as well as for hundreds of couples on their special day. Notably, he also competed in the Cincinnati DJ battles, where he finished in third place. Outside of DJing, Jeff can be found either in the gym, making music, or hanging out with his wife and cat.
Thanks for reading!
Matthew Campbell
Wedding MusicLetter
P.S. Check out the ultimate wedding music guide - “Wedding DJ Songs Planner”.