Corps-Style Marching/Drill/Maintaining Tempo

Tempo is a measure of time and synchronicity. At what time exactly does something occur, and how long does it last?

Maintaining a consistent tempo while executing drill is critical both to the visual performance (e.g. keeping all marchers synchronized in-step) and to the musical performance (e.g. ensuring all marchers are at the same part of the music). Being spread out on a field presents interesting timing challenges which are essentially unique to marching ensembles.

Challenges

When you go see your favorite band in concert, especially if it's got a large budget, the musicians will probably have in-ear monitors that feed tempos, cues, isolated audio, and other important information that may otherwise get lost in the noise from the crowd. For example, you can search on YouTube "In Ear Monitor Track" to find videos of what performers hear through their earpiece. It is a very common tool for musicians in concert, especially drummers.

But Marching Bands virtually never have in-ear monitors. Drum Corps International rules are very strict on who can have an in-ear monitor and what audio can be played in it. Tempos, cues, and anything else that's pre-recorded are forbidden.

Note

There is at least one example of in-ear monitors in Drum Corps: The Bluecoats in 2016 used earpieces for their front ensemble (the non-marching members with the xylophones and stuff).

They were being fed live audio of their drumset player to assist with extraordinarily technical splits in a particularly challenging listening environment.

The Listening Environment

Arguably the most fascinating challenge of Marching Band is the physical size of the stage. If two individuals are playing in a small jazz band together, it's natural for them to listen to one another. "My friend is going to play these notes, and I need to start playing when they finish." But when you're on a football field, it is hypothetically possible that you're listening to somebody over 100 yards away from you! At these distances, the speed of sound is no longer negligible.

Imagine two drummers are separated by 50 yards. The speed of sound is about 375 yards per second. If one drummer plays a note, the other drummer will not hear it for another 133 milliseconds. That is a short delay in absolute terms, but it's huge in terms of rhythmic precision! Consider that, if you're playing music at 180 beats per minute, 133 milliseconds is nearly an eighth note of delay! If the drummer is listening, they will be late, and the music will sound horrible.

The same goes for wind players too, and it can be especially disastrous when listening to people who are in front of you. Brass instruments are designed to push most of their sound in the direction of their bell. So imagine a mellophone section that must begin playing when the trumpets reach a certain point in their music, and imagine the trumpets are in front of the mellophones.

The Trumpets play their cue. Because their bells are pointed towards the audience, not much sound goes backwards towards the Mellophones
The Trumpet sound travels towards the audience. (133 milliseconds)
The sound bounces off the audience and echos back towards the field. (running total: 266 milliseconds)
The Mellophones hear the echo, and begin playing (this should have happened at the same time as step 1!)
The Mellophone sound passes the Trumpets, who already played that part about 300 milliseconds ago and aren't expecting the Mellophones to be here.
The Mellophone sound finally reaches the audience, nearly a half second after the audience already heard the Trumpet sound!

Not only does this sound horrible for the audience because the Mellophones are so behind; the Trumpets might get thrown completely off, because what they're hearing is coming at an incorrect time.

Tearing

When tempo maintenance goes wrong, the worst-case scenario is that the marchers get lost on where the ensemble is supposed to be. This is called Tearing, and it can happen for a few reasons:

Listening forward as in the Mellophone/Trumpet example above. Mellophones are late relative to the ensemble and Trumpets are unsure where in the music they're supposed to be.
Soloists come in at the wrong time. For example, if the Baritone section has a solo feature, but one or more people enter a measure early.
Tempo rushing/dragging. If the Tubas begin slowing down, they will be off relative to everybody else.
A change to the show was made, but some people accidentally did the old version

Tearing is extremely scary. Nobody has an in-ear monitor to cue where the ensemble should be. Everybody has a clearly defined routine they must perform with virtually no flexibility for improvisation. And because the visuals are such a key aspect of the performance, tears put the marchers in an impossible situation.

Can't align on music, because we disagree on where we are in the drill
Can't align on drill, because we disagree on where we are in the music
Can't communicate, because the disagreement is happening 50 yards away

When the ensemble tears, there is little hope for recovery. Ideally it happens near a natural reset point, like just before the end of a song. It can get so bad that the Drum Major has to stop everybody and communicate where in the show to resume.

All this to demonstrate that maintaining tempo is perhaps the single most important responsibility, and failure to do so can be catastrophic.

Solutions

With these challenges, how does a marching group maintain tempo?

The Source of Truth

One might assume that the Drum Major, the conductor standing up in front of everybody waving their arms, is the person who decides what the tempo is. That's a good assumption, but in general, it is technically incorrect.

The individual who sets the tempo for the entire group is the lead snare drummer, also called the "center snare." When the center snare is marching, the Drum Major's job is to look at the center snare's feet and relay that tempo to the rest of the ensemble. The Drum Major is in charge of tempo only when the center snare is not marching.

Note

Since symphonic orchestras aren't moving around on a football field, why do they still have a conductor? Can't they just listen in to each other?

Yes, they could! Especially at a professional level, symphonic orchestras could play just fine all by themselves. But there, conductors help in creating a unified interpretation of the music across the several dozen performers who are playing. How much exactly should we slow down? At what volume exactly should the flutes play; is this good or is it too much? Drum Majors also do this to an extent, but their primary responsibility is relaying tempo, and interpretation is secondary to that.

In Practice

Unlike the speed of sound, the speed of light is functionally instantaneous. With the drum major looking at the center snare, and the performers looking at the drum major, the performers will be perfectly aligned with the center snare.

So in short, that's the answer: The Center Snare sets the tempo, the Drum Major relays the tempo, and everyone else watches the Drum Major. If everyone does that, then everyone will be at the same spot, and it will sound nice for the audience.

Complications: More Listening Environments

The core problem we started with is still there. Even if our two drummers, spread 50 yards apart, are both looking at the drum major, there's still a significant delay between when one plays and the other hears. How does this get resolved?

The answer is that it doesn't get resolved. You simply cannot listen to anyone who is either far away from you or in front of you. You must reject the instinct to listen for tempo. The only sources of truth are the center snare and the Drum Major(s).

An unfortunate consequence is that the music may sound horrible from your perspective. It will sound like you are coming in late and that everything is failing to line up—because the sound literally takes a different amount of time to reach your ear depending on where everyone else is. But if everyone is aligning with the Drum Major(s), then it will reach the audience at the same time, and it will sound good for the audience.

Complications: Front and Backfield

Though it's also not exactly that simple. A football field is 53.3 yards wide, so it's hypothetically possible that one person is all the way up front near the audience and another person is all the way in the back. Even if both of these people watch the Drum Major and play at the exact same moment, the frontfield person will have their sound reach the audience ~133 milliseconds before the backfield sound reaches the audience.

Drill designers must be aware of this limitation. It should be exceptionally rare for marchers to actually be in a situation where they are playing with such a significant vertical spread. But in that event, the fix is for backfield players to "anticipate" the Drum Major a tiny bit. Consider the downbeat to be the moment just before the Drum Major actually signals a downbeat.

The only way to know how much exactly to anticipate is to guess and check during rehearsal. Music Directors should let marchers know if the vertical spread is causing a delay, and fine-tune the timing by running the relevant segment a couple times.

Complications: Audience in Different Seats

Technically, the audience is spread out just as far, or even farther, than the performers. We've been taking for granted that the audience is a homogenous entity. If a marcher is playing on the 30-yard line, there are some audience members who are also on that 30-yard line. There are some audience members on the 50-yard line. There are other audience members on the opposite 30-yard line.

This, unfortunately, is impossible to solve. The best that the marching ensemble can do is eliminate as much controllable error as possible, and prioritize the most important audience: the judges. Judges will sit in the press box, midfield high up and towards the back of the stands. Brass players will be instructed to point their bells towards the press box, or slightly below it—which is why seats midfield high up and towards the back command the highest ticket prices.

It's not all bad for audience with seats on the outskirts. The sound will be somewhat quieter, because the marchers are pointing their bell towards midfield. The only major issue with timing is when the marchers are spread very wide horizontally playing fast music with a lot of exposed notes.

Complications: Obstructions

Sometimes it's difficult for a marcher to see the Drum Major.

Maybe something else is blocking the view (another marcher? a spinning flag? a prop?)
Maybe the instrument itself is blocking the view (Mellophones and Tubas are most susceptible)
Maybe the marcher is watching the form to maintain drill shapes

Many groups address these obstructions by having more than one Drum Major. It is common for one person to be in the middle (say, the 50 yard line), and two Drum Majors to be on either side (say, on either 30 yard line).

If you're still obstructed, but there are people close behind you and they can see the Drum Major(s), it is acceptable to listen back to them for tempo. In terms of what the audience will hear, listening for tempo from people behind you is okay, because your sound begins moving just as their sound passes you, which makes both sounds reach the audience at the same time.

Between multiple Drum Majors and listening close behind you, there should never be a time when you have no source of true tempo. Your own internal metronome is good enough for any other short gaps, which should be too minor to cause any big problems like tearing.

Complications: Drumline versus Winds

While these principles are relevant for winds (brass and woodwinds), they are absolutely critical for the drumline. Winds usually have the advantage of playing and holding notes, which can hide many minor tempo discrepancies. If somebody comes in a hundred milliseconds late, it's probably unnoticeable, because their late entrance gets swallowed by the several other people who started playing on-time.

Wind players have the most to worry about with short, separated, and exposed notes. A beautiful example of tempo maintenance which combines everything previously discussed is the Bluecoats in 2023 performing "Bump". Wide horizontal spreads (Trumpet on the 20-yard line to trombone on the opposite 15-yard line), unusual rhythms, along with short and separated notes. When you listen to that excerpt, you can clearly see how obvious it would be if the rhythms were imprecise. Also imagine that the music probably sounds horrible from the performers' perspective, because everyone is so spread around.

In a drumline however, every note is short and separated. Drums cannot sustain tones, so it is very obvious if a drumline is imprecise. In fact, because these tempo demands are so stringent, it's often better for the drumline to listen to one another rather than looking at the Drum Major. With an instrument as snappy as a drum, the following considerations become relevant:

Watching the Drum Major is not ideal, because each individual player may have a slightly different interpretation of when exactly the Drum Major signals a downbeat. The best way to stay aligned is to listen to each other. This is why the Center Snare is the ultimate source of true tempo, and why the drumline almost always marches drill in a tight group: since the Center Snare is true tempo, and every individual drummer is never more than about 3 yards away from a fellow drummer, listening is a viable option.
So listening is very critical, but when doing drill, the listening environment is constantly changing. You might be listening to the person on your right, but they're circle around to your left and end 5 yards away from you, so you've got to adjust your ears mid-phrase.
You might be at the edge of the drumline, so you've got drums in one ear but brass in the other ear, and you must ignore the brass.
The snare drum you're listening to might be on top of a prop, so you hear the bottom drum head louder than the top head, which sounds a bit different.
You might be listening to a bass drum, whose playing is very disjointed because they are just one split of the overall bass drum part.

Drumline is often anecdotally considered the most difficult section of a Drum Corps because of the responsibilities of tempo maintenance, technical passages, exposed and relatively obvious mistakes, combined with much of the same visual responsibilities as the brassline.