Of the single-reed instruments, the "clari net" is the most important. It was invented by Christopher Denner of Nuremberg, in 1690, and embodies the very ancient principle, that of the 'squeakee reed, which is commonly made by children even at the present time.
Of the several forms of clarinets those in A- and B-flat are used by the modern orchestra, while the B-flat and E-flat instruments are used in military bands, in which their functions correspond to that of the violins in the orches tra. The C clarinet with its shrill tone is seldom used. Their color varies according to the register. The ordinary notes are eloquent, heroic and tender ; in the lower register they become spectral, and impressively sombre in the bass. Although the last instrument introduced into the orchestra, all the great composers wrote for it, and considered it favorably. With Mozart it was one of the leading instruments of the orchestra, and in his beautiful E-flat symphony, written in 1788,, clarinets are em ployed even in the place of the oboes.
As in the case of the double-reed wood wind instruments, in which the mouthpiece is used with a metal tube and gives the sarruso phone, the adaptation of the clarinet-reed to a brass tube gives the family of °saxophones,* invented by Adolph Sax in 1846. They re semble the clarinets very closely in shape; have a full, rich, penetrating tone-color, and are ex tensively used by the military bands of France and Belgium, and have also been used with great advantage in the French orchestras.
Of the °brass instruments,* the most import ant are the horns, cornets, trumpets, trombones and tubas. Two other forms, the ophicleide and the serpents, though frequently employed in the older orchestral scores, are now obsolete, having been entirely superseded by the tuba.
There are two important differences between the wood-wind and the brass instruments. In the former the tones are produced by vibrating air-columns, or by vibrating single or double reeds, and alterations of pitch are accomplished by shortening the air-columns, while in the lat ter the vibrations utilized are those of the play er's lips, which are pressed against a round, cup-like mouthpiece, and the air-column is lengthened to alter the pitch. The brass instru
ments are capable of giving a much larger num ber of partial tones naturally than the flutes, oboes and clarinets, which use only a few notes of the harmonic series, and derive such partial tones from the fundamental tones, or from the overtones. Horns and cornets furnish roman tic tone-coloring, and are effectively, used in connection with forest and hunting scenes, while the trumpets are employed to express brilliant martial passages depicting heroic deeds. Trombones and tubas are grand, sonorous tubes which afford a solemn and menacing tone-color to the splendor of a full orchestra, and are also advantageously used to depict coarse and brutal scenes. All of them are valuable components of modern military bands. Plate II illustrates various of wind instruments, developed from their original forms into perfect instru ments during the latter part of the 18th and the earlier part of the 19th centuries.
The instruments of percussion are those which are incapable of giving many tones, or playing definite melodies, like the stringed and wind instruments already described. They are of two classes — those that give an actual tone, such as the kettledrums, glockenspiel and xylo phone; and those without any definite pitch, such as the bass and small drums, tambourines, cymbals, castanets and triangles. Of these, the kettledrums are the most important, and, to gether with the cymbals, are extensively used to emphasize military effects; while the others serve to express those that are purely rhyth mical. For detailed descriptions of all of the instruments mentioned, see special articles under their respective titles; also ORCHESTRA, INSTRU etENTs OF THE. For descriptions of keyed in struments, see articles on the ORGAN and the PIANOFORTE.
For further detailed infor mation consult Elson, 'Orchestral Instruments and their Use' (Boston 1903) ; Hawkins, 'Gen eral History of the Science and Practice of Music' (London 1875) ; Hofmann, 'Katechis mus der Musikinstrumente' (Leipzig 1890) ; Vidal, 'Les Instruments a Archer) (Paris 1878), and Schletterer, Ahnen moderne: Musikinstrumente (Leipzig 1882).