Here I am to lay down the law. Well… I’m gonna try to and then feel good about myself. I’m noticing a plight of buzzword-driven analysis in the drumming world — hip terms that get thrown around with little rhyme or reason. There are four terms that have fallen victim to this: syncopation, polyrhythm, polymeter, and metric modulation. Some of these are used almost interchangeably, so let’s try to clear things up.

Syncopation

Trusty syncopation. Syncopation doesn’t get much thought amongst drummers — I suspect it’s because of Ted Reed’s Syncopation, a book that pretty much every drummer seems to go through within a year of picking up the instrument.

Syncopation is broadly defined as giving emphasis to a weak beat or offbeat, but that seems so ubiquitous and broad that it can’t describe anything meaningful, since every moment of popular music must be syncopated. And that’s approximately true; hitting the snare on 2 and 4 is technically syncopation, since 2 and 4 are considered weak beats in 4/4, and the snare backbeat gives them emphasis.

In day-to-day drumming discussions, I use syncopation to describe playing that sounds not only offbeat, but jagged, disorienting, or somehow unexpected. Something that really stands out from the song around it.

A classic example is “Nobody’s Fault But Mine” by Led Zeppelin, particularly around the 2:12 mark, when the band plays some consistent hits before the bass and drums start playing a dotted 8th pattern. The cowbell part in Blink–182’s “Feeling This,” which first shows up around 0:33 (check out my blog post about that tune), is more or less the same idea.

As far as drum fills go, check out “Semente” by Snarky Puppy, around the 1:35 mark.

While I tend to use syncopation to describe concise ideas, an entire section can feel syncopated if it obfuscates any strong beat of pocket. Listen to the main riffs of “Mind Spun” and “Arithmophobia” Animals as Leaders.

You could try to get into the minutiae of why these moments are syncopated, are further describe them as polyrhythms et al., but syncopation is broad, and those other concepts are narrow, so when in doubt, just say it’s syncopated.

Polyrhythm

Polyrhythm doesn’t really have a simple, well-established definition. It’s occasionally defined as two rhythms played at the same time. It’s in the name, but with that thinking, nearly every drum part you hear is polyrhythmic, including this:

Well, the two patterns must contain a number of notes that don’t divide evenly into each other. Obviously, two and one are evenly divisible. But what about two and three?

That’s a bingo. Two even notes are heard in the space where three even notes are.

So what’s the confusion? Well, see what happens if we “fill in” all the snare notes so that an accent pattern creates the “three” rhythm:

Is it still polyrhythmic? Many drummers would say yes, but I’d say no. The only time notes should line up in a polyrhythm is when the pattern starts over. But in the second example, the rhythm itself is just 8th notes over dotted quarter notes:

Here’s another example where accents are used to imply a five-over-four polyrhythm:

You can clearly see that the 16th and quarter notes align perfectly. Take all of those 16th notes out of the snare part, and now we have something resembling a true polyrhythm:

Polymeter

Polymeter might have the most straightforward definition: two time signatures that are played at once, typically split between different instruments:

In the above example, we have a piano part in 6/8 with the drums playing in 4/4. Of course, you wouldn’t actually write a full score with two different time signatures at the same time, since different instruments would be at different measures at the same point in the song. So one meter has to be mashed into another. Here’s the same example entirely in 6/8:

And in 4/4:

Polyrhythm Vs. Polymeter

There’s a bit of confusion regarding the difference between polymeter and polyrhythm. In my above example, the two different patterns are both built with the same rhythm, 8th notes; the key is that these different patterns are of different lengths and take up different amounts of time. The two different rhythms in a polyrhythm must start at the same time; that’s not the case with a polymeter.

Edit (July 2023): I recently came across an interesting visualization of polyrhythms, featuring dots navigating different shapes. I decided to whip up my own version of the animation, including both a polyrhythm and a polymeter:

Put another way, if your polyrhythm is being created by accents, it’s not a polyrhythm. Accents don’t change the actual rhythm. They do change how notes are grouped, much like time signatures do, which is why I will generally describe accent mischief as a polymeter, such as this one I introduced earlier:

Revisiting this example:

It’s a bit trickier. In complete isolation, it would sound like a 5–4 polyrhythm, and the exact rhythms and subdivisions would be open to interpretation. You could count it as written, or you could feel the snare drum as quarter notes and the kick drum as an 8th note quintuplet. On the other hand, if something was clearly marking a 4/4 downbeat, such as a kick drum accent (or something from the rest of the tune), then I would lean toward polymeter.

I actually think polymeters are more common in the hip, flashy, fusionoid drumming world than polyrhythms are. Many drummers “fill in” polyrhythms, i.e., accenting every seventh 16th note in 4/4 to create a 7–4 “polyrhythm,” but these patterns are not true polyrhythms.

Metric Modulation

This one drives me absolutely crazy, and for a while, it seemed inescapable on the internet. Everywhere I went, it was metric modulation this, metric modulation that, metric modulation here, metric modulation there… except, metric modulation nowhere.

The traditional definition of “metric modulation” means to change tempo using a relationship between two subdivisions. You’ll see it notated with a symbol that says something like “quarter note = dotted quarter note.” Like this:

If you listen to the audio example, you hear that the kick drum sounds like it stays at the same speed. The “beat” stays at the same speed, it’s just being counted differently. The notation tells the performer that, right at the time signature change, the dotted quarter note is to be played as fast as you were playing a quarter note in the measure prior. Here’s another example:

If you listen, you’ll find that this time, the tempo change is much more noticeable. The notation tells us that the half note is to be played as fast as the quarter note. The effect is that the tempo doubles in speed. Here’s a more jarring one, where the quarter note (after the marking) is to be played as fast as the quarter note triplet:

As you can imagine, these can get quite complicated, since any combination of notes can be used, such as tuplets or even notes combined with ties.

The point is that true metric modulations must involve tempo changes. However, drummers figured out some time ago that you can use accents and certain subdivisions to trick the listener into thinking that there’s been a tempo change, without actually changing tempo. Here’s a very common example:

The effect is more dramatic if the two patterns are swapped:

This is what has taken over the internet lately, using this approach to create rather awkward or contrasting feels between the drums and the rest of the song. Even more ridiculous, “modulation” is sometimes used to vaguely describe any sort of repeated or attention-grabbing syncopation, even ones more accurately described as polyrhythms or polymeters. Here’s a shuffle groove for two bars before a switch to a rather convoluted accent pattern:

A bitchin’ metric modulation, right? Well, if there’s no tempo change, I’m not calling it a metric modulation. Some may call this an “implied metric modulation,” which might be helpful, but you could just as well call it a polymeter. Or, once again… just say it’s syncopated.

And there you have it. I will be taking no questions!