INSTRUMENTS OF PERCUSSION. The instru ments of percussion may be divided into two principal classes: (A) Those which have definite Pitch; (B) those which have not. The former class comprises ( 1 ) the kettle-drums; (2) the glockenspiel; (3) the xylophone. The latter class includes: (1) the bass drum; (2) the small drums; (3) the tambourine; (4) the tamtam; (5) the cymbals; (6) the triangle; (7) the castanets, (See the separate articles.) The chief use of instruments of percussion is for marking the rhythm. Those instruments that are devoid of definite pitch are capable only of rhythmic figures; whereas the glockenspiel and xylophone can play melodic( figures as well. Of all the instruments of percussion the kettle drums are the most important and most generally used.
For description of the keyed instruments (pianoforte and organ), the reader is referred to the extensive special articles.
Under the above headings the instruments at present in use in the orchestra have been de scribed in their general features and especially in their relation to other members of the same family. Besides the instruments mentioned, many others have been in use in former times. There are still others in actual use, but as they are not employed for music of a high character, they have not been discussed. Then there is still another class of instruments reeently invented, which, however, have not yet come into general use, as the saxophone (q.v.). The following is a list of instruments of these classes: alpenhorn, bagpipe, basset-horn, bugle, eembal d'amore, chimes, clavichord, concertina, crowd, dulcimer, thigelhorn, glasschord, harpsichord, hurdy-gurdy, jews-harp, kazoo, krummhorn. In-, lute, lyre,
ocarina, psaltery. sarrusophone, saxophone, shawm, spinet. theorbo, viol, virginal. Instru ments of the nations of antiquity and of Oriental nations are treated in the special articles on the music of those nations.
Besides the instruments employed in musical performances, there are a few that are built solely for the purpose of acoustic experiments. These are (1) the monochord; (2) the siren; (3) the tuning-fork (qq.v.).
Among the most valuable works on the history of musical instruments may be mentioned: Wa sielewski, Geschichtc der Instrumentalmusik ion. Jahrhundert (Berlin, 1878) ; Comettant, La musique, les musieicns rt les instruments do musique chez les difffrents peoples do monde (Paris, 1869) : Vidal, Les, instruments a archet (ib., 1878) ; Sehletterer, Die Ahnen .moderncr 11 usikinstruninte (Leipzig, 1882) : Hofmann, m"afeehi,smos der usihinstrumcntc (i1).. 1890) ; John Hawkins. Ucacrai History of the Science and Practice of Music (originally published in five volumes in 1776, reprinted in two volumes, London, 1S75). This latter work is particularly valuable for its many cuts of now obsolete instru ments.