How to practice polyrhythms with the Soundbrenner metronome

Many musicians are often confused and intimidated by polyrhythms. Practicing them can be quite challenging, especially using traditional mechanical metronomes that don't allow for any customization. Fortunately, our app, The Metronome by Soundbrenner, offers a quick and easy method to get set up for polyrhythmic practice. If you don't have it yet, you can download it for free on both iOS and Android.

Our mobile app does not have a dedicated polyrhythm function. However, you can customize your time signatures, accents, and subdivisions so it is easier to play multiple rhythms concurrently. This method is also a great way to better visualize and understand polyrhythms for beginners who are new to music theory.

This article will serve as an introduction to polyrhythms and a tutorial on how to practice them using the Soundbrenner Metronome app.

What is a polyrhythm?

First, let’s quickly define what a polyrhythm is. Simply put, a polyrhythm consists of two or more contrasting rhythms played simultaneously. It is very rare to encounter a polyrhythm that makes use of more than two rhythms. So for the sake of this article, we will only focus on polyrhythms with two rhythms only. 

Polyrhythms are expressed in the format X:Y, where X is the number of beats per bar for rhythm 1 and Y is the number of beats per bar for rhythm 2. Y is usually the prevailing rhythm, and X is the rhythm that is superimposed on top of it.

For example, a 2:3 polyrhythm means that one rhythm will be playing three beats per bar while the other rhythm will be playing two beats per bar. Such a rhythm is commonly referred to as “two against three”.

_{Note: many people confuse polyrhythms with polymeters. They are not the same thing. Polyrhythms are simply two separate rhythms layered on top of one another, both in the same time signature. A polymeter occurs when different instruments are playing different time signatures but at the same tempo. This creates an effect where they are both in sync and out of sync at the same time.}

Formation of polyrhythms

A polyrhythm can only be created if Y is not a common multiple of X, or vice versa. For example, you cannot have a 2:4 polyrhythm because the second rhythm will perfectly subdivide into the first rhythm. This is similar to when one bar of 4 is equivalent to two bars of 2, like so: 

Therefore, polyrhythms are only possible when the two rhythms do not have any common factors other than 1. 

First, let's take a look at a 2:3 polyrhythm.

In order to understand how this works, we need to figure out how exactly the rhythms line up with one another. This is where subdivisions come into play. Since 3 is not perfectly divisible by 2 and 2 is not perfectly divisible by 3, we will need to subdivide the two rhythms such that they can be played together concurrently. 

This can be done by multiplying X and Y. This will result in the number Z which is a common multiple of both X and Y. So in our current example of the 2:3 polyrhythm, Z would be 6 since 

2 x 3 = 6.

Now that we have done this, we can easily visualize our polyrhythm. This will allow us to see how X and Y line up when they are placed in a bar with 6 subdivisions.

The chart above shows 1 bar split into 6 equally spaced beats (the common multiple of 3 and 2). Each cross represents a beat from its respective rhythm.

We can see that although the rhythms are different, they both line up on the 1 and play together every time the bar repeats. 

Practicing polyrhythms

To practice this polyrhythm, we can open the Soundbrenner app and set a time signature of 6/4, with an accent on the 1. The 6/4 time signature will ensure that we can hear 6 distinct beats. The accent will ensure that we know when the polyrhythm repeats.

Assume we are practicing this on a practice pad or snare drum. The right hand will play rhythm 1 and the left hand will play rhythm 2. Then the right hand will play on every 1st and 4th beat, while the left hand will play on every 1st, 3rd, and 5th beat. 

Let’s go through another example. Let’s say we want to play a 3:4 polyrhythm, where rhythm 1 plays 3 beats per bar and rhythm 2 plays 4 beats per bar.

Again, 3 and 4 do not divide into each other, so we have to multiply them together to give a common multiple of 12.

Once more, using the chart visualization method, we can see exactly how to play this polyrhythm when each bar is subdivided into 12 counts. The right hand plays on every 1st, 5th, and 9th count, while the left hand plays on every 1st, 4th, 7th, and 10th count. Again, the only time both hands play together is on the 1st beat of every bar. 

When practicing, make sure that every note is played together with a click from the metronome. There should not be any notes played during the off-beats. The whole purpose of subdividing the polyrhythm into a common multiple is to hear exactly when to play each note. This is easier than having to approximate based on your own internal clock.

Wrapping up

If you are having trouble with the auditory click track and would prefer to feel the beat, try practicing with the Soundbrenner Pulse or Core 2 instead. The Pulse will sync seamlessly with our mobile app via Bluetooth. You can use the app to set up your time signatures, accents, and subdivisions as shown above. The Core's tempo, time signature, subdivisions, and accents can all be customized directly from the watch face itself, without needing to be connected to the app.

You now have all the information you need to start playing polyrhythms. Be sure to experiment with different rhythms, not just the ones demonstrated in this article. Finally, remember that mastering polyrhythms takes time and a lot of practice. Incorporate them into your daily routine to train your muscle memory, and don't forget to practice with a metronome!