Ah yes, ’tis a beautiful day. The sun is shining, the sky is clear, and the birds are chirping in impassioned tones: “give us more music theory!” I acquiesce to their melodious siren song, but do intend to also impart my musical musings upon you, the reader. After all, music theory is not just for the birds.
Today we’ll be talking about two rhythmic concepts: polyrhythms and swing percentages.
First up, polyrhythms.
A polyrhythm can be defined as the simultaneous playing of one rhythmic value – such as straight eighth notes – against another contrasting value – such as triplets – over a single meter. Polyrhythms have deep roots in non-Western music traditions from Indonesian and African cultures. They are commonly found in contemporary rock and jazz.
The interplay and juxtaposition of seemingly opposing rhythms are what give polyrhythms their character. A common way to think of these patterns in musical notation is to envision/hear them as ratios. Triplets against eighth notes would have a ratio of 3:2. Other simple polyrhythms are 3:4, 4:3, 5:4, 7:8 and so on.
3:2 in Western notation:
4:3 in a different visualization:
Polyrhythms can become quite complex, and multi-layered. Take, for example, 2:3:4:5:6 (as heard toward the end of this video.) They can add an interesting rhythmic flare to music, and are worth checking out.
Next, swing percentages.
Even if we are not conscious of it, we all have a feeling for “swing” versus “straight.” If you’ve ever played in a jazz band, you are keenly aware of this stylistic difference. Classical composers of centuries’ past tend to prefer straight timing, whereas swing was all the rage in the 1930’s era of big bands.
Swing refers to a type of rhythm where alternating subdivisions are given unequal durations, creating a long-short-long-short pattern. A common type of swing is a triplet swing in which the first note has twice the length of the second note.
Triplet swing is just one of many possible ways that subdivisions can be swung. One way to conceptualize these variations is with percentages. A swing percentage refers to the percentage of the beat that is taken up by the first note. For example, 50% corresponds to perfectly straight time where both notes have an equal duration. 57% is septuplet swing. 60% is quintuplet swing. 62.5% is golden ratio swing. 66.6% is the aforementioned triplet swing. Want to swing harder? Try 80% on for size.
All of these percentages are valid in the right musical context, and can be found in jazz, rock, and electronically-produced music.
Now, with the knowledge of these niche yet powerful concepts, you are free to spread your wings and make a really sick beat.
“Polyrhythms have deep roots in non-Western music traditions from Indonesian and African cultures. They are commonly found in contemporary rock and jazz.” All throughout my time in Africa, I really listened and retained the unique rhymes and beats within their music and until now, I could not put a name to the distinctive sounds I was hearing. Very good read!