What is natural about that horn?

Nowadays there is plenty of concern over whether a product is natural or not. When an item has been modified by man it is often considered dangerous, and the horn was no exception to this when it underwent chromatic modifications in the nineteenth century. Notes outside the key of the music are called “chromatic” - not only were the trumpets and horns of the Baroque period limited to the key of the music, but they were also limited in other ways. It is strange to think that the loud instruments associated with pomp, nobility and the military, the horns and trumpets, were handicapped by having large gaps in their range where no reasonable notes could be produced. The only way that composers could write music that sounded good on these instruments was to write music for them in the register and key where they had notes to play. These available notes are known as the natural harmonics, and they are more numerous (and have greater excitement and risk) in the upper register of the instruments. The instruments were pitched in keys low enough for these notes to be reachable by human lips, so most of them are about twice as long as their modern counterparts which achieve the same pitches using lower harmonics.

There is not much that is natural about the alloy of brass: it is a mixture of copper and zinc, usually held together on the joints by lead solder. These metals are a man-made mixture, but the alloy has been with us a long time, and in the case of brass instruments they are designed to emulate and improve the acoustic qualities found in nature in the form of animal horns, hollowed out logs and certain sea-shells.

The horn and trumpet were first considered real members of the orchestra in the Baroque period, predominantly towards the end of the seventeenth century. At this time some skilled players were able to achieve a few chromatic notes by bending the existing natural harmonics with the lips. It was a rare technique that could do this, and the search was on to provide the instruments with a greater range of notes. Although nowadays we would describe those instruments as being natural horns or natural trumpets, in those days they were without the qualifying term “natural” because as yet there was no need to distinguish them from any other type.

In Bach’s music we occasionally find the term Corno da tirarsi or Tromba da tirarsi. This means Slide Horn or Slide Trumpet. Few examples of slide trumpets from this period exist, and no examples of slide horns survive, but it shows the attempt to add to the range of notes of these instruments.

The first chromatic notes regularly achieved on the horn were not down to the inventiveness of manufacturers, but players. In the mid-eighteenth century it became known that chromatic notes were obtainable by putting the hand inside the bell of the horn. The notes played with the bell uncovered by the hand were called the “natural notes”, and the covered ones “hand-stopped”. Trumpet players also adopted this technique for a while, and instruments were developed to accommodate this.

Although there was some opposition to the adoption of this technique, it was largely considered a good thing, particularly for horns, and there was a great deal of concern when the possibility of losing those characteristic stopped sounds became real with the invention of valves in the early nineteenth century. So great was this opposition in France that the valve horn was abandoned shortly after its introduction at the Paris Conservatoire, and classes there were confined to the Hand Horn for about sixty years. At this time the terms used for the valveless horn included Cor Simple, Natural Horn, Wald Horn, Inventions Horn and Hand Horn, whilst those with valves were known as Piston Horn, Ventil Horn and Cor à cylindres. The worry that with the invention of valves, the horn would be played without hand-stopping gradually diminished, but for those who like to hear the works of the masters with these stopped notes, orchestras like the Orchestra of the Age of Enlightenment have revived this possibility.

© Andrew Clark, OAE Co-Principal Horn, 2003.

A version of this article originally appeared in Enlightenment, the OAE Friends’ newsletter. To read more about natural horns, visit Andrew’s website.