ORCHESTRA. In ancient Greece the Opxj7arpa was the space between the auditorium and the proscenium or stage, in which were stationed the chorus and the instrumentalists. In its modern acceptation the word means either that portion of a the atre or concert-hall provided for the accommodation of the instru mentalists or the body of instrumentalists itself ; by extension in the U.S.A. it means the main floor of the theatre.
The modern orchestra is composed of (I) a basis of strings— first and second violins, violas, violoncellos and double basses; (2) flutes, sometimes including a piccolo; (3) the reed contingent, con sisting of two complete families, (a) the oboes with their tenors and basses (the cor anglais, the fagotto or bassoon and the con trafagotto or double bassoon), (b) the clarinets with their tenor and basses (the basset horn and the bass and pedal clarinets), with the addition sometimes of saxophones; (4) the brass wind, consisting of the horns, a group sometimes completed by the tenor and tenor-bass Wagner tubas, the trumpet or cornet, the trom bones (tenor, bass and contrabass), the tubas (tenor, bass and contrabass) ; (5) a harp or harps; (6) the percussion instruments, including the kettledrums, bells, Glockenspiel, cymbals, triangle, etc. ; to which are sometimes added a celesta and a pianoforte, to say nothing of such "extras" as the rattle employed by Richard Strauss in Till Eulenspiegel, the wind machine required by the same composer in Don Quixote, the iron chains introduced by Schonberg in his Gurrelieder, and so on.
Although most of the instruments from the older civilizations of Egypt, Chaldea, Persia, Phoenicia and of the Semitic races were known to the ancient Greeks, they did not share in any way their neighbours' love of orchestral effects, obtained by combin ing harps, lyres, guitars, tanburs, flutes, trumpets, bagpipes, cym bals, drums, etc., playing in unison or in octaves. The Greeks only cultivated to any extent the various kinds of citharas, lyres and auloi, and these were seldom used in concert. To the predilec tion of the Romans for wind instruments of all kinds we owe nearly all the wind instruments of the modern orchestra, each of which had its prototype among the instruments of the Roman empire : the flute, oboe and clarinet, in the tibia; the trombone and trumpet in the buccina ; the tubas in the tuba; and the French horn in the cornu and buccina.
The 4th century A.D. witnessed the downfall of the Roman drama and the debasement of instrumental music, which was placed under a ban by the Church. During the convulsions which the migrations of Goths, Vandals and Huns caused in Europe after the fall of Rome instrumental music was preserved from absolute extinction by wandering actors and musicians.
The earliest instrumental compositions extant are certain 15th century dances and pieces in contrapuntal style preserved in the libraries of Berlin and Munich. The late development of notation, which long remained exclusively in the hands of monks and troubadours, personally more concerned with vocal than with instrumental music, ensured the preservation of the former, while the latter was left unrecorded. But indications are not wanting of an independent energy and vitality which must surely have ex isted in unrecorded mediaeval instrumental music, since there is such evidence of this in the instruments themselves. It is, for example, significant of the attitude of the loth century instru mentalists towards musical progress that they at once assimilated Hucbald's innovation of the organum, a parallel succession of fourths and fifths, accompanied sometimes by the octave, for two or three voices respectively, and that they produced in the same century the organistrum, named after Hucbald's organum.
At the time of the revival of the drama with music, afterwards modified and known as opera, at the end of the 16th century, there was as yet no orchestra in our sense of the word, but merely an abundance of instruments used in concert for special effects, without balance or grouping; small positive organs, regals, harp sichords, lutes, theorbos, archlutes, chittarone (bass and contra bass lutes), guitars, viols, lyras da braccio and da gamba, psal teries, citterns, harps, flutes, recorders, cornets, trumpets and trombones, drums and cymbals.