Instruments of percussion possessing definite and variable pitch are represented primarily by the kettle-drums, which are constant and indispensable members of the orchestra. The early Hackbrett or dulcimer might also be classed under this heading, which further includes the various sets of bells, such as the carillon or Glockenspiel of Chinese origin, together with the Stahlspiel or Lyra, and the Xylophone. * * * * * This sketch demonstrates the fact that the early evolution of instruments went hand in hand with that of music in general and is subject to identical hypotheses. With the dawn of secular music, the development of instrumental construction and mechanism is focused upon the sixteenth century, with emphasis upon the anterior practice of employing complete homogeneous groups. In order to cover the entire ground, this survey of the development of musical instruments has necessarily transgressed the bounds of the sixteenth century perspective. And since we are about to recontinue a critical review of the orchestra as inherited by Monteverde, it will be well to remember that in his day the only orchestral instruments in the modern sense of the word were violins and viols, harps, flutes, pommers, cornetti, trumpets, trombones. In combination with these, lutes, guitars, organs, the clavichord and the harpsichord were still employed. (Summary on page 26.) CHAPTER IV. BEGINNINGS OF ORCHESTRATION. I. CLAUDIO MONTEVERDE[1] (1567-1643) is justly styled the founder of the modern orchestra; but although modern orchestral organization owes its substratum of solidity and balance of tone to him, only indirectly was he led to attain this end, for his paramount objective was artistic expression. Naturally, the employment of artistically grouped instruments appealed to him as the most flexible conveyance for expressive thought. Again, Monteverde was instinctively a dramatic writer, so that as a matter of course the histrionic efforts of the Florentine experimentalists attracted him. Finally, when Monteverde entered upon his dramatic career after having already become celebrated as a writer of madrigals and of other vocal forms, pure choral music as perfected by Palestrina and Lasso was at its zenith, and instrumentation in its elementary state was inseparable from the drama,--it being understood that the early attempts at oratorio in the _stilo rappresentativo_ were built on the same general principles as the early operas, without differentiation in musical or instrumental treatment. Nor were the incipient efforts at orchestral accompaniment to religious worship of sufficient importance to be taken into consideration. Therefore, _Monteverde's_ contribution to the chain of æsthetic and practical musical development consists of his successful search after expressive and dramatic effects and his reconstruction of the orchestra. He also broke away from the Church Modes, employed a system of harmony nearer