How Brass Instruments Work

by ReverbLxnd in Trumpet

How brass instruments work

What gives the trumpet its bold, stately sound that is so hard to ignore? What gives the tuba its deep, gut-shaking sound? And what makes the trombone so jazzy? How do brass instruments work?

The answer lies not in brass these instruments are made of, but in the journey air takes from the musicians lungs to the instrument’s bell.

Let’s see how brass instruments actually work and how musicians use them to create an amazing palette of pitches.

The brass instruments

You probably already know that there are many brass instruments. There’s the a huge list from the tuba through to the cornet, flugelhorn, trombone, and many more.

The oldest brass instrument in existence today is the trumpet, which as first created around 1500 B.C.

The tuba, by contrast, is the youngest brass instrument, which as invented as recently as 1835, and brought into orchestras as a replacement of the Ophicleide.

The 4 main brass instruments (in order of pitch)

In order of pitch, the four main brass instruments are:

  1. The trumpet
  2. The trombone
  3. The french horn
  4. The tuba

The trumpet is the highest pitched instrument in the brass family while the tuba is the lowest, with the trombonr and french horn somewhere in between.

How brass instruments work

Like any sound, music is simply vibrations traveling through air.

Instruments are classified according to how those vibrations are produced.

Percussion instruments are struck, string instruments are plucked or bowed, woodwind instruments have air blown against a reed, for brass instruments however, the vibration comes directy from the musicians lips.

One of the first things a brass player must learn is breath control.

After breathing in, a musician tries to hold their lips loosely closed while blowing enough air to cause them to vibrate.

The buzz

The escaping air meets resistance from the lip muscles to create the vibration as it passes through an opening called the aperture. This vibration forms a sound brass players called the buzz.

You should read this step-by-step lip buzzing guide, and this in-depth mouthpiece buzzing guide if you want how to do this on a brass instrument. Buzzing techniques are similarr across all brass instruments.

The embouchure

When a mouthpiece is help up to those vibrating lips, it holds the lips in place to create a setup. This setup is what brass players call an embouchure.

A good embouchure refines the buzz amplifying the vibration at various frequencies.

A good embouchure happens to be one of the most critical techniques you need to not just get right, but get right with some consistency because all your playing builds on top of it.

Here’s the how to form a reliable consistent brass embouchure in just 4 easy steps, the same exact 4-step technique followed by famous brass players all over the world.

Once you know the pieces of the puzzle, how they fit together and what everything does, the only thing holding you from forming a consistently reliable brass embouchure is practice.

The harmonic series

Things get really interesting depending on what instrument is attached to that mouthpiece.

A brass instrument’s body is essentially a tube that resonates with the air column pulling through it. The way that sound waves travel through columns forms a limited pattern of pitches known as the harmonic series.

The notes of the harmonic series are spaced further apart at the lower end but coming closer together as the pitch increases.

Adjusting pitch on brass instruments

The musician can alter the pitch of a note in the series through slight contractions of the lips and alterations to air volume and speed (pressure).

Slower, low pressure, sighing air produces lower pitches, and faster, high pressure air produces higher pitches in the series.

But any sigle harmonic series has gaps where pitches are missing and the versatility of brass instruments lies in their ability to switch between multiple series.

On instruments like the trumpet, valves can be lowered to increase the length of tubing the air travels through. On a trombone, this is done by extending the slide.

In both of these instances, lengthening the tubing stretches the vibrating air column — reducing the frequency of vibration — resulting in a lower pitch.

This is why the tuba, the largest brass instrument, is also the one capable of playing the lowest notes.

Changing the instrument length shifts its harmonic series. While slight variations of the airflow and the players embouchure produces different notes.

What started as a deep breath and vibrating buzz on the lips has now been transformed into a bold and brassy tune.

Using skillful manipulation of every part of this process, brass musicians create an amazing palette of pitches that can be heard in musical genres across the globe.

By harnessing the power of natural resonance in a flexible and controllable way, brass instruments are great examples of the fusion of human creativity and acoustics.

Articulation on brass instruments

There are a lot of ways of using your tongue to play brass instruments besides adjusting pitch.

To play staccato on brass instruments, you need to use your tongue to stop the air. This is referred to as tonguing a note.

If you don’t use your tongue at the start of a note, for instance, you get a soft breath attack.

You can vibrato, growl, flutter toungue, ghost-toungue, and a raft of other techniques on brass instruments with just tonguing alone.

I’ve written a couple of guides on most of these techniques such as this vibrato guide, and this flutter tonguing guide amongst many others.

You can play very low notes by having your tongue low and flat behind your teeth, and you can play very high notes by having your tongue almost against the roof of your mouth.

In all these techniques, the fundamental concepts remain the same because they all follow the laws of physics.

I’ve written a couple of guides on articulation including the single tonguing, double tonguing and triple tonguing series. Have a look if want to learn how to tonguing a brass instrument step-by-step.


I've been a musician and brought in my stuff for mixing and mastering, I've been my own producer where I wrote, recorded, mixed and sold my own stuff. Now, I'm *mostly* an audio engineer, where I only record and mix for clients. I'm currently based in Berlin, Germany, where I operate ReverbLand out of. Got a question? DM me on Instagram or Twitter @reverblxnd everywhere, or shoot me an email [email protected]. I'd love to hear from you.

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