Polyrhythm is a word used to describe the harmoniously rhythmic combination of voices heard in a song often associated with Latin American music, jazz, African drumming, and Indian Classical music (to name a few). It would be a mistake to only associate polyrhythm to a specific genre or style of music. The truth is that we can identify polyrhythm in nearly all forms of music.
Most of the polyrhythms heard in popular music today are considered to be very danceable. It should come as no surprise then that these popular rhythms originated in Africa. But drums and rhythm served a higher purpose in African culture than just dance music: they were also used (and still are) for long-distance communication and ceremony with their rhythms designed by the natural language and speech patterns of the tribe(s). When you realize this rich history and the relationship between African and modern pop rhythms, the emotional role it has in music makes sense.
What makes a Polyrhythm?
If we separate the word poly from polyrhythm: poly means “multi,” or “more than one.” A polyrhythm is essentially a combination of at least two or more rhythms performed at the exact time and tempo.
Also known as composite rhythm, polyrhythm is any combination of two or more rhythms, each of which has its own independent succession of musical events.
This musical expression can last a segment, or it can exist and change throughout an entire song. A polyrhythm can be simple, in a 4/4 groove such as the drums we hear in the jungle-like rhythm from the classic Bow Wow Wow hit, “I Want Candy.” Or it can be very complex using multiple voices and odd time signatures like the relationship between Sitar and Tabla in Indian classical music.
Why is it important?
Like tonal harmony in a chord or progression, polyrhythm in music adds to the depth and emotion in a song. Without it, music may feel incomplete. And popular music would sound extremely different.
As neuroscientist Daniel J. Levitin writes in his book, “This Is Your Brain On Music,” we know that rhythmic patterns play a game with the pleasure system of the brain, feeding our neural pathways with dopamine as a reward. Without rhythm in music, the entire world would be a very different place!
Some genres and styles of music get by just fine without polyrhythm, such as Gregorian chanting. As much as I like to listen to the monks when I meditate, the rhythm will always be where the heart is.
Syncopation vs. Polyrhythm
Is it instrument-specific?
A piano or a guitar is a polyphonic instrument capable of playing multiple voices, rhythms, and syncopations at simultaneous or opposing intervals. These instruments are capable of producing polyrhythm without accompaniment.
Understanding and creating polyrhythms can be a confusing concept. Here is a video that explains how to create a basic 4 against 3 polyrhythm using your DAW. The 4-beat polyrhythm uses quarter notes, and the 3-beat rhythm uses dotted quarter notes. When you combine the two rhythms at the same time, as demonstrated in the video, you have a polyrhythm.