The Structure of the Horn
The structure of the horn
Single, double, triple
These sound more like mattress sizes, but single, double, and triple are the names of the various horn structures. The two big categories are the single horn and double horn, and within the single horn group there is the F horn, B♭horn, and high-F horn, that plays one octave above the F horn. The F horn has an effective length of 360 cm when none of the levers are depressed, while the B♭horn is 270 cm, and the high-F, 180 cm. The longest horn is the F horn, and it has the lowest tonal range.
A double horn is an instrument with two tubes of different pitches. Most commonly, a double horn consists of an F tube and a B♭tube.
A "descant double" has a B♭tube and a high-F tube, and in this case, descant means "high pitched tone."
A triple horn has all three pipes: F, B♭, and high-F tube. The appearance of the horn also changes as the number tubes increases. Let's listen to the tone of the F and B♭horns.

B♭ single horn

F/B♭full-double horn

F/B♭/High F triple horn
F tube tone
B♭ tube tone
Range of the horn

What is the difference between semi-double and full-double?
On the left is a semi-double horn, on the right, a full-double. Though these two have the same range, they are built differently.

F/B♭semi-double horn

F/B♭full-double horn
The total length of the tube is a little shorter on the semi-double. The diagram below shows the length of the tubes and the position of the three valves. The valves on a horn are arranged in two tiers, but for simplicity's sake they are evenly spaced.
Full-double and semi-double horn structure

A tube length of 275 cm is necessary to produce a low B♭, and the lower F requires a tube length of 370 cm.
On the full-double horn, the air can flow through either the B♭ branch or the F branch. However, the B♭ branch is 30 cm long, which leaves a tube of 245 cm (275 minus 30) that is also used when playing the low F. This means that the F branch must be 125 cm long (370 - 245).
In contrast, on the semi-double horn, a 275 cm tube, which is required to play the low B♭, is the primary tube on the instrument. To play a low F, air flows through the F branch, returns to the beginning, and passes through the entire length of the 275 cm tube. In other words, the F branch must be 95 cm long (370 minus 275), which is 30 cm shorter (125 minus 95) than the full-double.
Compared to the full-double horn, the semi-double horn is 0.1 to 0.2 kilograms lighter. However, there are drawbacks. When playing the low F, the air passes the valve section of the F tube and then passes the valve section of the B♭ tube. This means that air has to pass many uneven spots inside the tube, which has an effect on the tone.
The first semi-double and full-double horns were created by famous horn makers such as Alexander and Kruspe around 1900. Below is a list of the names of all the parts of the full double horn.
Names of the parts on the F/B♭ double horn
The Gesttopft key
Hand-stopping is one of the techniques that is unique to the horn, and that is used to change the pitch of the instrument.
However, sometimes the pitch becomes slightly higher, and there is no appropriate alternate fingering. Thus, the B♭single horn and the B♭/High F descant double horn has an extra valve to alter the pitch slightly, called a "gesttopft key."

The stomach and the boot
At the Yamaha factory, they call the convoluted tube on the right "the stomach," and the protruding tube on the left "the boot." These nicknames seem fitting somehow. These tubes are frequently removed, even during performances, to remove the water that collects in them, and horn players are very fond of them.

The sparkle of a silver horn
The horn, like other members of the brass family, is made from yellow brass, which has a yellow-gold color, or from gold brass, which has a reddish-gold color. However, the horn's body is sometimes made from nickel silver, which is another characteristic unique to the horn. A horn made entirely from nickel silver is quite impressive.

What's different about the timbre of a Vienna horn?
Two reasons for the very different timbre of the Vienna horn from normal horns with rotary valves are the narrower (11mm) bore size of the Vienna horn and the taper of the bell and mouthpiece, which are nothing like those of the standard horn. In addition to those differences, a different valve system and the presence of a bogen also have an impact.
The final important point of difference is that while the Vienna horn is fundamentally in F, normal horns are most often double and triple horns are in B flat.
What is a clutch valve?
A clutch valve is a valve that is opened or closed manually. In contrast to a more standard valve that is operated by a lever and is returned to its original position by a spring, a clutch valve stays open when it has been opened, and stays closed when it has been closed.
Musical Instrument Guide : Horn Contents
Origins
Structure
How to Play
How the Instrument is Made
Choosing an Instrument
Trivia
- Famous horn works
- Concertos
- Mesmerizing fifths
- What does a very long horn sound like?
- The visual effect of "bells up"
- Mozart loved a good prank
- Is that the nature of the horn?
- An instrument by day, and a drinking mug by night
- Horn players can play the Wagner tuba, despite the name
- Why are horns included in woodwind quintets?
- What do you call someone who plays a horn?
- The reason that alto horns are used in brass bands
- What is a Vienna horn?
- Garlands do not deaden sound
- What is the Knopf model?
- New instruments have just been washed