The four-over-three polyrhythm comprises four equally spaced notes and three equally spaced notes played simultaneously. We can build one by using a subdivision that both sides of the rhythm can fit within evenly. A measure of 16th notes in 3/4 gives us twelve notes that are evenly divisible by both four and three. By playing quarter notes, we get the three side of the polyrhythm. The four side is created by accenting every third 16th note.
Exercise 1 demonstrates a four-over-three polyrhythm applied to the bass drum and snare with a 16th-note hi-hat pattern that ties the rhythm together.
In the previous example, both sides of the polyrhythm start on the beat. Within a 16th-note framework, you can displace the four side to start on either the “e” or “&” of beat 1. If you start Exercise 1 on either beat 2 or beat 3, you’ll see these permutations.
The possibilities get especially interesting when you displace the four side by one 32nd note, as notated in Exercise 2. Exercises 3 and 4 demonstrate the two remaining offbeat 32nd-note positions.
Practice these exercises slowly, count the 16th notes out loud, and focus on making the four side of the polyrhythm even. You’re looking for the patterns to groove on autopilot until the four side of the polyrhythm feels evenly spaced. Keep your hi-hat and bass drum solid while running through all six variations.
When practicing advanced rhythmic concepts, developing them within a groove gives us a musical context. If you alternate between an ordinary 16th-note hi-hat beat and the exercises in this lesson, you can home in on how the pocket is supposed to feel. Make sure the polyrhythm remains consistent.
Next we’ll incorporate a familiar ride pattern. Our hi-hat foot will play the “&” of each beat and represent the three side.
Practice exercises 5–7 by alternating each pattern with a straightforward groove, but maintain the notated hi-hat and ride cymbal pattern throughout both phrases. Try to maintain the same pulse from the basic groove when you play the polyrhythmic variations.
Once you’ve mastered Exercises 5–7, try accenting each snare note individually. For example, play Exercise 5 and ghost all the snare notes except the third. Do this for each snare note in the exercise, and come up with your own grooves that feature your favorite accents.
This next exercise adds a bass drum ostinato and moves the four side of the polyrhythm around the drumkit.
Next let’s explore all of the possible permutations of this rhythm by playing a double bass pattern and splitting the four-over-three polyrhythm between our hands. In Exercise 9, the four side starts on the beat with our left hand on a rack tom. The three side, which so far has been represented by a quarter note on the bass drum or hi-hat foot, can also be displaced to any of the eight 32nd-note partials within each beat. We’ll push the three side forward by one 32nd note with our right hand on a floor tom between the first and second bass drum notes of each beat.
Similar to how we accented each individual note of the four side in Exercises 5–7, try replacing each of the rack tom notes in Exercise 9 with the snare. In Exercise 10, the fourth rack tom note is played as a snare accent to create a syncopated groove. Be sure to practice these examples into and out of more standard 16th-note double bass grooves.
The next example pushes the four side forward by one 32nd note. The polyrhythm is now played entirely between the 16th-note double bass pattern. Go slowly, practice with a metronome, and make sure the rhythm sits evenly. Once comfortable, move each partial of the polyrhythm to an accented snare to isolate and solidify the feel of each note.
With your right hand between the first and second kick of each beat, experiment with the remaining permutations of the four side on the rack tom.
Within this double bass framework, you can work your way through each permutation of both sides of the polyrhythm. The application of these rhythms and the context in which you practice them is only limited by your imagination. Exercise 12 demonstrates an offbeat variation that forms a tom melody between the bass drum pattern.
Now we’ll voice the three side on the “e” of each beat and play four aggressive snare accents. Exercise 13 demonstrates a displaced feel when alternated with a more common 16th-note double bass groove. In Exercise 14, the snare pattern is pushed forward one 32nd note and lands entirely between the double bass pattern.
Come up with your own ways of voicing these rhythms musically while you work through the remaining variations. Think dynamically and musically while you explore these new rhythms to expand your own creativity.
Aaron Edgar plays with the Canadian prog-metal band Third Ion and is a session drummer, clinician, and author. He teaches weekly live lessons on Drumeo.com. You can find his book, Boom!!, as well as information on how to sign up for private lessons, at aaronedgardrum.com.