The Different Parts Of A French Horn: The Anatomy And Structure Explained

Written by Lisa Taylor
Last updated

From its humble beginnings as a simple instrument to its present-day use and many parts, the Horn has become widely used in orchestras worldwide.

This instrument has many features and 13 feet of coiled tubing for a single horn and 22 1/2 feet for the double Horn.

In this guide, we’re going to take a closer look at all the different parts of a french horn, their function, what they’re made of and how they affect the sound. Let’s get started.

Anatomy of a French Horn

Anatomy of a French Horn

Essentially, the french horn is a long piece of brass piping that begins with a mouthpiece and ends with a flared bell.

But there are lots of different types of french horn, each with different lengths of piping and valves.

Here are the common parts found on horns.


Placed on the Hornists lips while playing, the mouthpiece is an essential part of all brass instruments.

This small, removable, funnel-shaped device helps produce the sound by vibrating the player’s lips while directing the airflow.

Made with different sizes and materials to fit the player’s needs, the anatomy of a Horn mouthpiece consists of its diameter, rim, cup, bore, backbore, and shank.

Although brass is the most common material, other mouthpiece materials include Lexan plastic, titanium, wood and stainless steel.

In addition, the plating on metal mouthpieces consists of either silver or gold.

This part is interchangeable.

Mouthpiece Receiver

The mouthpiece receiver is a small metal cylinder that holds the mouthpiece in place while the Horn is played.

This receiver fused to one end of the leadpipe connects the mouthpiece to the rest of the instrument.


The brass tubing that runs from the mouthpiece receiver to the first tuning slide, the leadpipe, takes the air from the hornist to the Horn.

Finger Hook

Located at the top of the Horn just above the valves, the finger hook is a sturdy metal hook that enables the player to hold the instrument steady while using the valves.

Single horns often include a thumb hook used for the same purpose.

Main Tuning Slide(s)

Located in the back of the Horn with the single Horn with one and the double Horn two, the main tuning slides play an essential role in the instrument’s intonation.

The player moves these c-shaped metal tubes to adjust the instrument’s intonation.

In addition, water keys that empty the instrument’s condensation, located on the main tuning slide of a single Horn and the smaller slide of the double Horn, make it convenient for the player.

Water Key

The water key is a small lever located on the main tuning slide.

This key, easily pressed to uncover a small hole in the main tuning slide, helps the player get rid of the extra condensation that has built up in the Horn.

Valve Levers

Valve levers, also known as valve keys, work together with the rotary valves to change the Horn’s notes while being played.

By using string or another mechanism, these levers help spin a corresponding cylinder inside a rotary valve.

Horn String

Horn string serves as a crucial lifeline between the valve levers and rotary valves and an overall functional instrument.

Called a string, cord, or line wire, this specially made lifeline is eight inches in length threaded through a small hole in the lever extension, around a couple of set screws and rotary post.

Occasionally, the strings will break, and the Hornist needs to replace the broken string with a new one.

Rotary Valves

Usually numbering three or four, the rotary valves are hard metal cylinders that contain holes in certain spots.

These holes become exposed when pressing the corresponding valve lever.

The valves are the first, second and third valves, with the first located closest to the player when playing.

In the case of a double horn, a fourth valve, known as a thumb valve, is located closest to the player.

This valve, by the pressing of its lever, switches the Horn from F to B flat.

Some Horns have the thumb valve located the farthest away from the player, even though the lever is closest.

When playing a piece of music, the Horn player uses a combination of different fingerings and different amounts of air pressure to play the varying pitches.

The valves direct the air stream into one or more of the valve slides and the holes move to reroute the air in different sizing of air circuits depending on the playing, therefore changing the length of the instrument’s tubing.

Valve Caps

The valve caps cover the rotary valves on a Horn and they help keep debris away from the valves as debris will adversely affect the valves.

Valve Slides

As an assistant to the rotary valves, the valve slides play a vital role in the instrument as they help by directing the airflow into a precise point to produce the desired notes.

These valve slides correspond with the rotary valves and are named the first, second and third valve slides in a single Horn.

Another set of valve slides on a double Horn, located under the first set of valve slides, is the first, second, and third Bb valve slides.

The thumb valve also has a valve slide located closest to the player while playing.

The valve slides are removable, and the player can make micro-adjustments for tuning and remove them for cleaning purposes.

Bell Pipe

The bell pipe is where the sound builds in the instrument before the bell.


Amplifying, shaping, and scattering the sound waves to the listeners, the bell of the Horn is the widest point of the instrument.

In addition, the bell of the French Horn is designed to optimize the tone production of the Horn.

Since the bell has been experimented with for centuries, it has developed a standard shape.

This shape enhances tone, volume, and clarity.

Flare is a term used by instrument makers to describe horn size instead of Horn size.

While playing, the player places their right hand inside the Horn as it serves a practical and acoustical purpose.

The right-hand holds the instrument steady while it controls the pitch and the sound of the Horn.

This hand is also critical in the technique known as stopped Horn when the player completely closes the bell off with their right hand to create a unique sound.

Some Horns come with detachable bells, which makes transport more accessible.

Summing up the French Horn’s Parts

With its many parts and accessories, the Horn is a complex and fascinating instrument from mouthpiece to bell.

Instrument makers devote their craftsmanship to making all these parts and materials to precise specifications to make the best practicing and performing experiences possible for the Hornist.

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Lisa is a professional musician who has been playing french horn and various other brass instruments for the last 20 years. She has an undergraduate and masters degree in music and now teaches and performs all over the US with orchestras, brass bands and chamber groups.