This Section
next (3) STRINGED INSTRUMENTS.
We now come to the third group of instruments in our elementary classification. This is the group which sets up vibrations in the air by means of stretched strings. Orchestrally, it is the most complex group and the one that demands the greatest attention from the student. However, from our present purely scientific point of view, it is remarkably simple, and may be easily explained in a few sentences. In every case the stretched strings are of course in contact with the air. They cannot set the air in vibration until they themselves are first put in motion. The only subdivision possible is therefore based on the methods by which the player excites the strings. These methods are three in number.
First Method.
By plucking. In these instruments either the. finger is used (as in the Harp or Guitar), or a plectrum (as in the Mandoline)*
Second Method.
By striking. In these instruments a hammer, or a series of hammers, is employed. The Dulcimer and the Pianoforte are the most familiar examples of this method.
Third Method.
By contact with a prepared moving surface. In these instruments either a horse-hair bow is used (as in the Violin family), or a wheel-and-handle mechanism (as in the ancient Organistrum and the modern Hurdy-Gurdy).
We shall now take the four groups of orchestral instruments, beginning with the simplest, the " Percussion," and going on through the " Brass" and the " Wood-Wind" to the most complex, the " Strings." A short preliminary chapter of a general character will be placed before each of these sections. In this chapter the common historical development of the Instrumental group will, whenever possible, be traced. This is not, however, always feasible. It can be done in the case of the Brass instruments and the Violin family. For, though there are exceptions in the general technical development of both these Instrumental groups, these exceptions can easily be explained and brought into line with the rest of the history. For instance, in the " Brass " the general course of progress has been from the Natural outdoor instrument through the era of " crooks" to the period of "valves." The Trombone family is the chief exception. But the Trombones obey just the same physical laws as the other Brass Instruments in the production of their "Harmonics." The slide mechanism is their main differentiating feature. In a preliminary sketch, therefore, they can quite well be treated in company with the Trumpets and Horns.