That the operatic orchestra should have taken the lead was perfectly natural. When vocal polyphony was deposed from its supremacy, instrumental music was in its infancy. Only the organ had achieved anything approaching independence, and that was because all the leading composers had been writing for the church and knew the church instrument. For practice at home they used the clavichord, one of the forerunners of the piano, and they began presently to compose special music for it, but in the style of their organ music. Gradually they fell into the way of writing for small groups of instruments, and after a time the orchestra found its way from the opera house to the church, and the orchestrally accompanied mass came into existence. But meanwhile the composers who wrote for the clavier, with the aid of those who wrote for the solo violin, were fashioning a form, and after a time the sonata began to assume a definite shape. Now it was borne in upon composers that their auditors would not arrive at the opera in time to hear the overture, for operatic publics were much the same then as they are now; and the poor composers had recourse to writing their overtures so that they could be played independently and having them performed at concerts. As these overtures were written in a form founded upon the principles of the sonata form, nothing was more natural than that gradually composers should be led to the composition of complete sonatas for orchestra, and a sonata for orchestra is a symphony. In the middle of the eighteenth century, then, after Sebastian Bach had carried the piano solo through the splendors of his "Well Tempered Clavichord," and the piano sonata had attained something like defined shape, we see Stammitz, Gossec, and, at length, Haydn producing thin, tentative weakly orchestrated sonatas for orchestra, and the real development of independent orchestral composition began. This was nearly a century and a half after the birth of the orchestra as an adjunct to the opera, and the same length of time after the beginning of independent composition for the clavichord. In other words, although the modern art of music may fairly be said to have begun at least as early as the beginning of the twelfth century, when the fundamental principles of counterpoint were enunciated by the French masters, the most splendid and powerful of all musical instruments, the orchestra, is to-day in its infancy. For if the masters of vocal polyphony took some twelve centuries to elaborate their science, it is fair to presume that, even though the general laws of music are now firmly established, the technics of the orchestra and of orchestral composition, which are a little over a hundred years old, are yet by no means fully understood.