In 1753, a man named Hampel that was apart of the Dresden orchestra came out with his celebrated “Invention Horn." Changeable slides directly in the body of the horn somewhat used as tuning slides are inserted in horns today. He also found that inserting the musician’s hand in the bell not only softened the tone but raised it to a semi-tone. While this discovery was made in the early 1700’s composers did not write music for the hand horn until early in the 19th century. It was not until almost the 20th century that the hand horn was entirely abandoned in favor of the valve horn.
There are two types of French Horns that people use when playing. The single french horn is most used when first learning to play. Single horns use a single set of tubes connected to the valves. This allows for simplicity of use and a much lighter weight. But the problem with it is that its hard to play a note higher than above third-space C. So thats where the double french horn came in (pictured above). German horn maker Ed. Kruspe a prototype of the "double horn" in 1897. Double french horn is for when wanting to reach high ranges when playing. 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.
The mellophone is an instrument that french horn players would play if they were in marching band. The picture up above is a type of mellophone in F alto. This type of mellophone was used widely in the United States from before the turn of the century until before WWII. It features piston valves and fingered with the right hand, this instrument is an octave shorter than a standard single F horn and was generally used to play horn parts in amateur groups. While it is easier to play, it lacks some of the tone we associate with the horn.
This is the type of mellophone that is used today in most marching bands. It is in F alto just like the classic mellophone but uses a more trumpet like mouth piece and is built with a more different shape. It is also has piston valves and not regular valves like the french horn. Sometime in 2007 high schools and collages then began to use this french horn. This mellophone has similarities in the way it plays to the early mellophone but it lacks tone that we associate with the horn. Theres another mellophone that called the B-flat marching horn it has a sound that is similar to the french horn.