The brass choir consists of trumpets, which are soprano instruments, French horns (bass to alto), trombones (bass, baritone, and tenor), and tubas (bass). This band is capable of independent performance, or of being joined in a body with the wood, as in military music, or of combining with the strings on the plan seen in its infancy in Handel's "Hallelujah" chorus. The strings, of course, contain all the elements necessary to independence or combination. The modern orchestra, however, has gained enormously in power from the development of methods of using parts of the separate choirs independently or in combination. For instance, flutes, clarinets, and bass clarinet can produce rich four-part harmony, and so can play alone. Flutes, oboes, and bassoons can do the same thing and produce a wholly different instrumental color. Bassoons and French horns make fine deep-toned harmonies; and four French horns can play alone in full harmony. Any of these little groups can be joined with strings to get a new quality of tone. Thus it is not difficult to see that the modern orchestra offers to the composer a great variety of instrumental combinations, giving him a remarkable range of coloring, and it is equally plain that these conditions have been gradually developed by successive composers since the days of Monteverde. Chapter XII The Classic Orchestral Composers "Sinfonia avanti l'Opera"--Its development into the overture--Effect of this on orchestral composition--The classical symphony--Haydn and his achievements--Exploring the secrets of orchestral writing--Mozart and his notable system--Condition of the symphony when Beethoven began writing.