French horn

Single horns use a single set of tubes connected to the valves. This allows for simplicity of use and a much lighter weight. They are usually in the keys of F or B♭, although many F horns have longer slides to tune them to E♭, and almost all B♭ horns have a valve to put them in the key of A. The problem with single horns is the inevitable choice between accuracy or tone – while the F horn has the "typical" horn sound, above third-space C accuracy is a concern for the majority of players because, by its nature, one plays high in the horn's harmonic series where the overtones are closer together. This led to the development of the B♭ horn, which, although easier to play accurately, has a less desirable sound in the mid and especially the low register where it is not able to play all of the notes. The solution has been the development of the double horn, which combines the two into one horn with a single lead pipe and bell. Both main types of single horns are still used today as student models because they are cheaper and lighter than double horns. In addition, the single B♭ horns are sometimes used in solo and chamber performances and the single F survives orchestrally as the Vienna horn. Additionally, single F alto and B♭ alto descants are used in the performance of some baroque horn concertos and F, B♭ and F alto singles are occasionally used by jazz performers.

Dennis Brain's benchmark recordings of the Mozart Horn Concerti were made on a single B♭ instrument by Gebr. Alexander, now on display at the Royal Academy of Music in London.

The valves of a Conn 6D double horn. The three lever keys (above the large valves) can be depressed toward the large outer tube. The thumb key (near the left-most valve) moves inward toward the three finger keys.

Scheme of a double horn (view from underneath)

1. Mouthpiece
2. Leadpipe, where the mouthpiece is placed
3. Adjustable handrest
4. Water key (also called a spit valve)
5. Fourth valve to change between F and B♭ pitches
6. Valve levers, operated with the left hand
7. Rotary valves
8. Slides, for tuning each valve
9. Long tubing for F pitch with slide
10. General slide
11. Short tubing for B♭ pitch with slide
12. Bellpipe
13. Bell; the right hand is cupped inside this

Despite the introduction of valves, the single F horn proved difficult for use in the highest range, where the partials grew closer and closer, making accuracy a great challenge. An early solution was simply to use a horn of higher pitch—usually B♭. The use of the F versus the B♭ horn was extensively debated among horn players of the late 19th century, until the German horn maker Ed. Kruspe (namesake of his family's brass instrument firm) produced a prototype of the "double horn" in 1897.

The double horn also combines two instruments into a single frame: the original horn in F, and a second, higher horn keyed in B♭. By using a fourth valve (usually operated by the thumb), the horn player can quickly switch from the deep, warm tones of the F horn to the higher, brighter tones of the B♭ horn, or vice versa, as the horn player may choose to have the horn set into B♭ by default by making a simple adjustment to the valves. The two sets of tones are commonly called "sides" of the horn. Using the fourth valve not only changes the basic length (and thus the harmonic series and pitch) of the instrument, it also causes the three main valves to use proportionate slide lengths.[13]

In the US, the two most common styles ("wraps") of double horns are named Kruspe and Geyer/Knopf, after the first instrument makers who developed and standardized them. The Kruspe wrap locates the B♭ change valve above the first valve, near the thumb. The Geyer wrap has the change valve behind the third valve, near the little finger (although the valve's trigger is still played with the thumb). In effect, the air flows in a completely different direction on the other model. Kruspe wrap horns tend to be larger in the bell throat than the Geyer wrap horns. Typically, Kruspe models are constructed from nickel silver (also called German silver, an alloy of copper, nickel and zinc, containing no actual silver) while Geyer horns tend to be of yellow brass. Both models have their own strengths and weaknesses, and while the choice of instrument is very personal, an orchestral horn section is usually found to have either one or the other, owing to the differences in tone color, response, and projection of the two different styles.

In Europe the most popular horns are arguably those made by Gebr. Alexander, of Mainz (particularly the Alexander 103), and those made by Paxman in London. In Germany and the Benelux countries, the Alex 103 is extremely popular. These horns do not fit strictly into the Kruspe or Knopf camps, but have features of both. Alexander prefers the traditional medium bell size, which they have produced for many years, whereas Paxman do offer their models in a range of bell throat sizes. In the United States, the Conn 8D, a mass-produced instrument based on the Kruspe design, has been extremely popular in many areas (New York, Los Angeles, Cleveland, Philadelphia). Since roughly the early 1990s, however, for reasons ranging from changing tastes to a general dislike of Conn's newer 8Ds, orchestras have been moving away from the popular Conn 8D. Geyer model horns (by Carl Geyer, Karl Hill, Keith Berg, Steve Lewis, Jerry Lechniuk, Dan Rauch, and Ricco-Kuhn) are used in other areas (San Francisco, Chicago, Pittsburgh, Boston, Houston). The CF Schmidt double, with its unique piston change valve, is occasionally found in sections playing Geyer/Knopf model equipment.

The horn, although not large, is awkward in its shape and does not lend itself well to transport where space is shared or limited, especially on planes. To compensate, horn makers can make the bell detachable; this allows for smaller and more manageable horn cases.

A natural horn has no valves, but can be tuned to a different key by inserting different tubing, as during a rest period.

The natural horn is the ancestor of the modern horn. It is essentially descended from hunting horns, with its pitch controlled by air speed, aperture (opening of the lips through which air passes) and the use of the right hand moving around, as well as in and out of the bell. Although a few recent composers have written specifically for the natural horn (e.g., György Ligeti's Hamburg Concerto), today it is played primarily as a period instrument. The natural horn can only play from a single harmonic series at a time because there is only one length of tubing available to the horn player. A proficient player can indeed alter the pitch by partially muting the bell with the right hand, thus enabling the player to reach some notes that are not part of the instrument's natural harmonic series – of course this technique also affects the quality of the tone. The player has a choice of key by using crooks to change the length of tubing.[14]

Vienna horn

The Vienna horn is a special horn used primarily in Vienna, Austria. Instead of using rotary valves or piston valves, it uses the pumpenvalve (or Vienna valve), which is a double-piston operating inside the valve slides, and usually situated on the opposite side of the corpus from the player's left hand, and operated by a long pushrod. Unlike the modern horn, which has grown considerably larger internally (for a bigger, broader, and louder tone), and considerably heavier (with the addition of valves and tubing in the case of the double horn) the Vienna horn very closely mimics the size and weight of the natural horn, (although the valves do add some weight, they are lighter than rotary valves) even using crooks in the front of the horn, between the mouthpiece and the instrument. Although instead of the full range of keys, Vienna horn players usually use an F crook and it is looked down upon to use others, though switching to an A or B♭ crook for higher pitched music does happen on occasion. Vienna horns are often used with funnel shaped mouthpieces similar to those used on the natural horn, with very little (if any) backbore and a very thin rim. The Viennese horn requires very specialized technique and can be quite challenging to play, even for accomplished players of modern horns. The Vienna horn has a warmer, softer sound than the modern horn. Its pumpenvalves facilitate a continuous transition between notes (glissando); conversely, a more precise operating of the valves is required to avoid notes that sound out of tune.

Two instruments are called a mellophone. The first is an instrument shaped somewhat like a horn, in that it is formed in a circle. It has piston valves and is played with the right hand on the valves. Manufacturing of this instrument sharply decreased in the middle of the 20th century, and this mellophone (or mellophonium) rarely appears today.

The second instrument is used in modern brass bands and marching bands, and is more accurately called a "marching mellophone" or mellophone. A derivative of the F alto horn, it is keyed in F. It is shaped like a flugelhorn, with piston valves played with the right hand and a forward-pointing bell. These horns are generally considered better marching instruments than regular horns because their position is more stable on the mouth, they project better, and they weigh less. It is primarily used as the middle voice of drum and bugle corps. Though they are usually played with a V-cup cornet-like mouthpiece, their range overlaps the common playing range of the horn. This mouthpiece switch makes the mellophone louder, less mellow, and more brassy and brilliant, making it more appropriate for marching bands. Often now with the use of converters, traditional conical horn mouthpieces are used to achieve the more mellow sound of a horn to make the marching band sound more like a concert band.

As they are pitched in F or G and their range overlaps that of the horn, mellophones can be used in place of the horn in brass and marching band settings. Mellophones are, however, sometimes unpopular with horn players because the mouthpiece change can be difficult and requires a different embouchure. Mouthpiece adapters are available so that a horn mouthpiece can fit into the mellophone lead pipe, but this does not compensate for the many differences that a horn player must adapt to. The "feel" of the mellophone can be foreign to a horn player. Another unfamiliar aspect of the mellophone is that it is designed to be played with the right hand instead of the left (though it can be played with the left). Intonation can also be an issue with the mellophone.

While horn players may be asked to play the mellophone, it is unlikely that the instrument was ever intended as a substitute for the horn, mainly because of the fundamental differences described.[15] As an instrument it compromises between the ability to sound like a horn, while being used like a trumpet or flugelhorn, a tradeoff that sacrifices acoustic properties for ergonomics.

The marching horn is quite similar to the mellophone in shape and appearance, but is pitched in the key of B♭, the same as the B♭ side of a double horn. It is also available in F alto, one octave above the F side of a double horn. The marching horn is also played with a horn mouthpiece (unlike the mellophone, which needs an adapter to fit the horn mouthpiece). These instruments are primarily used in marching bands so the sound comes from a forward-facing bell, as dissipation of the sound from the backward-facing bell becomes a concern in open-air environments. Many college marching bands and drum corps, however, use mellophones instead, which, with many marching bands, better balance the tone of the other brass instruments; additionally, mellophones require less special training of trumpeters, who considerably outnumber horn players.[16]

The Wagner tuba is a rare brass instrument that is essentially a horn modified to have a larger bell throat and a vertical bell. Despite its name, it is generally not considered part of the tuba family. Invented for Richard Wagner specifically for his work Der Ring des Nibelungen, it has since been written for by various other composers, including Bruckner, Stravinsky and Richard Strauss. It uses a horn mouthpiece and is available as a single tuba in B♭ or F, or, more recently, as a double tuba similar to the double horn. Its common range is similar to that of the euphonium, but its possible range is the same as that of the horn, extending from low F♯, below the bass clef staff to high C above the treble staff when read in F. These low pedals are substantially easier to play on the Wagner tuba than on the horn. Wagner viewed the regular horn as a woodwind rather than a brass instrument, evidenced by his placing of the horn parts in his orchestral scores in the woodwind group and not in their usual place above the trumpets in the brass section.

The horn is most often used as an orchestral and concert band instrument, with its singular tone being employed by composers to achieve specific effects. Leopold Mozart, for example, used horns to signify the hunt, as in his Jagdsinfonie (hunting symphony). Telemann wrote much for the horn, and it features prominently in the work of Handel and in Bach's Brandenburg Concerto no. 1. Once the technique of hand-stopping had been developed, allowing fully chromatic playing, composers began to write seriously for the horn. Gustav Mahler made great use of the horn's uniquely haunting and distant sound in his symphonies, notably the famous Nachtmusik (serenade) section of his Symphony No. 7.

Many composers have written works that have become favorites in the horn repertoire. These include Poulenc (Elegie) and Saint-Saëns (Morceau de Concert for horn and orchestra, op. 94 and Romance, op. 36). Others, particularly Wolfgang Amadeus Mozart, whose friend Joseph Leutgeb was a noted horn player, wrote extensively for the instrument, including concerti and other solo works. Mozart's A Musical Joke satirizes the limitations of contemporary horn playing, including the risk of selecting the wrong crook by mistake.

The development of the valve horn was exploited by romantic composers such as Bruckner, Mahler, and Richard Strauss, whose father was a well-known professional horn player. Strauss's Till Eulenspiegel's Merry Pranks contains one of the best known horn solos from this period, relying on the chromatic facility of the valved horn. Schumann's Konzertstück for four horns and orchestra is a notable three-movement work. Brahms had a lifelong love-affair with the instrument, with many prominently featured parts throughout his four symphonies. However players today typically play Brahms on modern valved instruments.

There is an abundance of chamber music repertoire for horn. It is a standard member of the wind quintet and brass quintet, and often appears in other configurations, such as Brahms' Horn Trio for violin, horn and piano (for which, however, Brahms specified the natural horn). Also, the horn can be used by itself in a horn ensemble or "horn choir". The horn choir is especially practical because the extended range of the horn provides the composer or arranger with more possibilities, registerally, sonically, and contrapuntally.