SYMPHONY (Lat. symphonia, from Gk. crvi,(0covia, unison of sound. harmony, from cOa owvos, symphonos, agreeing in sound, harmonious, from afv, syn, together + ocovh. plain, sound, voice). In music, a word used in two different senses: (1) The instrumental introduction and termination of a vocal composition. sometimes called ritornello: (2) a composition for a full orchestra. consisting generally of four move ments. The most usual though not unvarying order of movements is a brilliant allegro, ushered in by a slow introduction, an adagio or andante, a scherzo with its trio, and the finale, again an allegro. For the origin of the modern symphony we must go back to the beginnings of opera early in the seventeenth century, when the name Sinfori-ia was given to the short instnnnental prelude which preceded the opera. The early his tory of the symphony is, therefore, that of the overture (q.v.). About the middle of the eight
eenth century composers began to write separate sin f onic exclusively for concert performance. The three parts of the older overture, which had then only a loose connection, were entirely detached and became separate movements. Haydn introduced a fourth movement., the minuet (q.v.), which he inserted before the finale. He also adopted for the first movement the sonata form (q.v.). By individualizing the separate instru ments and grouping them in families Haydn also established the symphony orchestra and thus made the symphony what it is to-day. Beethoven extended the form considerably, particularly the development section of the first movement, and also replaced the minuet by the more elab orate scherzo (q.v.). Beethoven also increased the orchestra considerably. (See ORCHESTRA.)