Rhythmic Time Warping: Metric Modulation
If you’re into more technical styles of music like jazz-fusion, progressive rock or progressive metal, you may have reached a point in a song where the groove seemingly changed speeds, but it was buttery smooth and sounded pretty cool.
We can create the effect of jumping to a faster or slower speed, and even change time signatures in the process, using a technique known as metric modulation.
With pitched instruments, modulation refers to shifting the tonal center of music (moving to a different key signature). Metric modulation refers to shifting the rhythmic center of music. This shift is achieved by using rhythmic pivot points, which allow us to navigate seamlessly between different tempos and feels.
At the time this post was written, lots of drummers on TikTok and Instagram were covering the Tears for Fears classic “Everybody Wants to Rule the World,” but they completely change the feel of the groove by applying metric modulation. It sounds really nice, but how exactly does it work? The Loudlands team is here to answer that question.
Rhythmic Pivot Points
We’ll start with a measure of 8th note triplets in 4/4. There are 12 triplets in each measure. Typically, we feel them as 4 beats divided into 3 parts each so the metric accent (where we feel the underlying pulse) aligns on each beat. But we can move the metric accent by playing an accent once every 4 triplets, effectively creating 3 groupings each divided into 4 parts. The triplets always move at one steady pace. We’re just changing where we feel the larger underlying pulse.
The math checks out; whether we play 4 groupings of 3 strokes, or 3 groupings of 4 strokes (determined by the accents), it all still fits within a single measure of 8th triplets in 4/4. However, grouping the triplets into 4s feels and sounds more like playing a measure of 16th notes in 3/4. To practice, play continuous triplets, but alternate each measure between playing the accents on each beat (once every 3 triplets), and once every 4 triplets. Count out loud as you play to better internalize your sense of beat 1 since that’s where everything meets up again.
Let’s use a basic groove to apply this concept. We’re essentially going to take a simple rock beat (based on 8th notes) and superimpose it into a triplet rate. Ultimately, it’ll feel like we’re speeding up, but it will still fit evenly into 4 beats. It all works by pivoting around the underlying triplets.
To get there, we’ll start by playing the beat as usual (kick on 1 and 3, snare on 2 and 4, 8th notes on the hihats). Then we’ll switch to playing continuous triplets on the hihats. When that’s locked in, switch the kick and snare so they align with every 2 strokes on the hihats instead of every 3. The old triplet rate essentially becomes the new 8th note rate. We change the feel by pivoting around the different triplet accent groupings. It should feel like playing a measure of 8th notes in 6/4, but at a faster speed than where you started.
All of the below exercises are demonstrated in the video to the right. Here’s the prgoression:
The last line in the progression feels like the below groove . . .
When you feel good playing that beat superimposed into triplets, try playing the kick and snare at half the frequency (once every 4 triplets). Now, it takes 2 measures before everything lines up again. It should feel like playing a big, slower measure of 16th notes in 6/4. Notice how the snare lands on beat 1 of the second measure. I use that beat as a sort of “checkpoint” to prevent myself from losing track of the count throughout the phrase.
It sounds like this . . .
But it feels like this . . .
From there, play the hihats at half the frequency. In technical terms, the original 8th note groove is now superimposed into a quarter note triplet rate. It still feels like a big, slower measure of 6/4, but now with what feel like 8th notes on the hihats instead of 16ths on the hihats.
It sounds like this . . .
But it feels like this, just at half the speed compared to superimposing the groove into 8th note triplets.
To modulate even further from the original feel, we can easily pivot into 6/8 using the quarter note triplet rate. Simply play the kick right on beat 1, and the snare right on beat 3 (but it feels like beat 4 of 6). This phrase goes back to resolving every measure as opposed to every 2 measures.
It sounds like this . . .
But it feels like this . . .
Pivoting the Other Way
All of the above examples hinge around triplets, but we can apply the same concept to any other rhythmic rate. Let’s work with 16th notes in 3/4. There are 12 16th notes in every measure. Typically, 16th notes are thought of as groups of 4, but we can play an accent every 3 16th notes to make the measure feel more like 4 beats of triplets. Doing so allows us to modulate in the opposite direction as before. Instead of playing 6/4 “inside” of 4/4, we can play 4/4 “inside” of 3/4.
To calibrate the general cadence, play steady 16th notes in 3/4 and alternate each measure between playing accents on each beat, and accents every 3 16th notes. There’s a total of 12 16th notes in each measure, so we switch between grouping the 16ths in 4s (accenting on each beat), and grouping them in 3s. The goal is to feel the 16ths grouped in 3s as if they’re 4 beats of triplets. The below groove exercises are demonstrated in the video to the right.
We can gradually modulate into a 4/4 groove using the same process as before. We’ll start with a groove that’s definitively in 3/4. Play 8th notes on the hihats, hit the snare on beats 2 and 3, and play the kick every 3 16th notes. Even though the kick starts off playing 4 evenly spaced hits through the measure, the snare placement really anchors the feel in 3.
Next, switch to playing the snare on only the ‘&’ of beat 2. The ‘&’ of 2 is the halfway point in a measure of 3/4, which is important for tricking ourselves into hearing 4 beats inside each measure. This particular pattern feels like 6/8 to me, but the “4” element will soon become much more obvious.
It sounds like this . . .
But it feels like this . . .
Reduce the hihats to a quarter note rhythm while keeping the same pattern between the kick and snare. Now, the kick and snare play 4 beats spaced evenly against 3 beats on the hihats, creating a 4-against-3 polyrhythm. Try to use the phrase “pass the bread and butter” to keep the polyrhythm cadence in your ear. At this point, the “4” element begins to cut through a bit more. Your ear will begin getting pulled away from 3.
This is where things get a little trippy. Next, change the hihats so they bind to the kick and snare. It should sound and feel like playing steady 8th notes spaced over the measure, but it’s actually a continuous dotted 8th note rhythm. Remove the 2nd and 3rd kick from each measure to open up the feel a bit more. It should be much easier to trick your ear into hearing the groove as though it’s in 4.
These beats sound like this . . .
But feel like this . . .
While you likely won’t encounter metric modulation too much, it’s an excellent way to improve your internal sense of time while also offering different ways of navigating a given space. You’ll find time feels much more flexible. Patterns that you previously played exclusively as 16th notes can be phrased in triplets (and vice versa - triplet patterns phrased as 16ths) to breathe new life into things you’re already comfortable playing. With enough practice, you’ll be able to effortlessly weave between different tempos and feels without impeding the flow.
To dive deeper into the applications of metric modulation and other rhythmic concepts, drum lessons with a professional instructor will provide a structured path forward. Schedule a trial drum lesson near Watertown to get closer to your goals!