Polyrhythms, which are two contrasting subdivisions played simultaneously, can create beautifully hypnotic, entrancing patterns that dance around the pulse. They can also weave themselves into complete and utter chaos. Sometimes, when hidden subtly enough, polyrhythms enhance the music more subliminally. In recent years, bands like Meshuggah, Animals as Leaders, and Tool have played a major role in keeping these patterns popular. For progressive drummers, learning polyrhythms is a rite of passage.

When you’re beginning to learn polyrhythms, you need to have a handle on independence, and your time has to be solid. You also must be ready to work your mental muscle—the brain. The best way to begin mastering polyrhythms is to break them down into their most basic form. Whether you’re already a polyrhythm ninja looking to fine-tune your skills or you’re simply poly-curious, working through the following steps will put you well on your way to twisting rhythms like never before.

Polyrhythmic Formula

We’re going to focus on a very precise method for determining, notating, and playing polyrhythms. At the core of this approach is what I call the polyrhythmic formula. It’s a three-step process that takes the top and bottom numbers from your polyrhythm and spits out exactly what you need to know to master them.

The first polyrhythm we’re going to break down is four over three.

Step 1: Take the bottom number, which in this case is three, and use that to create a quarter-note-based time signature. For four over three, this would be 3/4 time. Play quarter notes on the bass drum to outline the time signature.

Step 2: Now use the top number, which in this case is four, to determine your subdivision. Four means 16th notes. (In other polyrhythms, three will mean 8th-note triplets and two will mean 8th notes.)

Step 3: Take the bottom number again, and use it to determine the spacing you’re going to use within the subdivision. For our four-over-three example, hit the snare on every third 16th note. This gives you the complete polyrhythm, with the snare outlining the four and the bass drum outlining the three.

That process can be used to break down any polyrhythm into its essential parts. To begin practicing the polyrhythm, start by hitting quarter notes with the bass drum, and play all of the 16th notes on the snare while counting out loud. Then accent every third note (1, a, &, e).

Once you have that mastered, remove the unaccented notes, leaving only the four notes of the four-over-three polyrhythm. Counting out loud might seem hard in the beginning, but you will form a deeper understanding of the rhythm, and you will internalize the polyrhythm more easily.

It’s also vital that you feel the quarter note as your pulse throughout the exercises, so make sure to really put some leg into it. Don’t let yourself start to feel the snare rhythm as the pulse; your rhythmic perspective is just as important as the notes themselves.

Go as slowly as necessary to count and coordinate the pattern. If you have trouble, start with only the snare part. Then add the bass drum notes one by one. Once you have the polyrhythm committed to muscle memory, turn on a metronome to help you refine and perfect the rhythm.

It’s important to note that once you’ve internalized four over three using quarter notes, you can begin to use the polyrhythm on smaller subdivisions, such as 16ths over 8th-note triplets, which is the same rhythm, only played over a single quarter note instead of three.

Now let’s see what happens when we reverse the numbers and work with the three-over-four polyrhythm.

Step 1: The bottom number is four, which gives us 4/4 time.

Step 2: The top is three, so use 8th-note triplets as your subdivision.

Step 3: Accent every fourth note of the triplet to give you three equally spaced notes over the four quarter notes.

The Evil Twin

What’s especially interesting about the two rhythms you just learned is that without any musical context, they sound identical. If you were to hear someone play these rhythms individually, you wouldn’t be able to tell one from the other. In most cases, when you’re dealing with these equal yet opposite polyrhythmic pairs, you’ll find that one will be drastically more challenging to internalize than the other—that’s the evil twin.

Five Over Four

Let’s use the polyrhythmic formula to break down one of the most commonly misinterpreted polyrhythms: five over four.

Step 1: The bottom number is four, which gives us 4/4 time.

Step 2: The top number is five, so our subdivision is quintuplets (five 16th notes in the space of one quarter note).

Step 3: Accent every fourth note of the quintuplets to create the five-note part of the polyrhythm.

Unless you’ve been playing quintuplets for a long time, the notation in Example 7 probably looks terrifying. This is the “evil twin” version. Now let’s break down the opposite polyrhythm: four over five.

Step 1: The bottom number is five, which gives us 5/4 time.

Step 2: The top number is four, so we’ll use 16th notes for the subdivision.

Step 3: Accent every fifth 16th note to create the four-note part of the polyrhythm.

Because it’s based in the more familiar subdivision of 16th notes, four over five is drastically easier to play than five over four. But it’s easy to lose your perspective with these polyrhythms, even if you’re working with a metronome. To get the most out of the exercises, make sure you take each polyrhythm in and out of your favorite grooves so you learn how to apply it in a musical context.

Don’t forget to try the formula with other polyrhythms as well, like five over three, five over two, seven over four, and so on.

Aaron Edgar plays with the Canadian prog-metal band Third Ion and is a session drummer, clinician, and author. You can find his book, Boom!!, as well as information on how to sign up for weekly live lessons, at aaronedgardrum.com.