What I've learned about the trombone

Go back<br>What I've learned about the trombone<br>Posted on:February 2, 2026 | at 06:54 AM<br>I’ve been playing the trombone since fourth grade. Today, I’m going to share what I’ve learned about, especially the technical aspects of playing such an instrument.

But first, what’s a trombone?

To understand why playing the trombone is so different, let’s first look at the instrument itself.

, via Wikimedia Commons" href="https://commons.wikimedia.org/wiki/File:Yamaha_Tenor_trombone_YSL-891Z_(re-crop).jpg">

Pictured here is a Yamaha tenor trombone. It’s very simple to assemble as it’s just 2 parts: the horn and the large tuning slide.

The trombone is the only brass instrument in a classical orchestra (I specify classical because variations such as the superbone also exist) where the main mode of pitch control is by moving the tuning slide . This means that, like string instruments (violin, viola, cello, etc), the pitch is continuous: I will get into why this is important later. But for now, one obvious advantage is that this allows us to do “real” glissandos, where the pitch smoothly transitions from one note to another.

As a brass instrument, you also “buzz” into the metal mouthpiece in order to play the trombone. “Buzzing” is the act of vibrating the lips against the mouthpiece to produce sound. If you just relax your lips and blow air (without vocalizing any pitch), that’s pretty close to what we call a “buzz”.

On a piano, you just press a key to play a note. For a trombone, you change the “slide position” where extending it makes a lower note.

Of course, since there’s only 7 slide positions (where 1st position is where the slide is fully retracted and the 7th is where the slide is fully extended), you would also need to adjust your embouchure (the way you shape your lips and tongue) to get to different “partials” to hit higher or lower notes.

To understand how that works (one of the hardest parts of playing a brass instrument), we need to look at the standing waves inside the trombone.

Side note: while the mechanics of this is technically the same for all wind instruments, the trombone is also unique in that it’s the most visually simple example of this system.

Physics!

When you buzz into the mouthpiece, you create a standing wave (vibrating air column) inside the trombone, which produces a specific pitch. The trombone can be modeled as a tube with one end open (the bell) and the other end closed (the mouthpiece which you are playing into).

Image courtesy of Dan Russell, licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

For now, the equation that’s useful here is

f=v4Lf = \frac{v}{4L}f=4Lv​<br>Where fff is the frequency, vvv is the speed of sound, and LLL is the length of the air column (the length of the slide).

Since pitch is frequency, and frequency is inversely proportional to the length of slide, extending the slide decreases the frequency, and thus lowers the pitch. Simple, right?

Uh, how about the notes beyond the seven positions?

Those notes need to be accessed with different “partials” achieved by changing your embouchure (lip and mouth technique).

Look at what the other diagrams are showing. When you play a note on a trombone (or any instrument actually), you’re not just playing the fundamental frequency (which is the main pitch you hear), but also a series of higher frequencies called overtones or harmonics . These overtones contribute to the unique timbre of the instrument and are why every instrument sounds different, even if they’re playing the exact same note.

Since the vibration of our lips is what creates the standing wave inside the trombone, changing the speed of our lips (e.g. by making it tighter) will “change the fundamental frequency” of the standing wave: if the frequency of our lips resonates (i.e. matches frequency) with one of the overtones, it amplifies it, making it sound like the “new fundamental frequency.” Yes: that means the higher we go, there will be “less” (or at least audible) overtones in the sound, making the tone sound more pure and closer to a pure sine wave.

By the way, when I say changing the speed of our lips is what selects the partial, while it’s technically true, it’s not a good way to teach technique.

Why not?

Just like how playing the piano isn’t just moving a finger up and down (even technically that’s all what’s happening) but instead involving the whole arm, to effectively control your trombone playing, you need to involve your tongue as well.

In fact, even if your lips are the main source of sound, your tongue actually does a lot of work in helping your lips with managing the air speed. Overstressing the lips is one of the most common mistakes beginners make when trying to reach the high partials. We call the overall technique of how you control your face to play into a wind instrument embouchure , and good embouchure is important for good sound.

Speaking...