The performers should feel that he feels, comprehends, and is moved; then his emotion communicates itself to those whom he directs, his inward fire warms them, his electric glow animates them, his force of impulse excites them; he throws around him the vital irradiations of musical art. If he is inert and frozen, on the contrary, he paralyzes all about him, like those floating masses of the polar seas, the approach of which is perceived through the sudden cooling of the atmosphere.
His task is a complicated one. He has not only to conduct, in the spirit of the author's intentions, a work with which the performers have already become acquainted, but he must also introduce new compositions and help the performers to master them. He has to criticise the errors and defects of each during the rehearsals, and to organize the resources at his disposal in such a way as to make the best use he can of them with the utmost promptitude; for, in the majority of European cities nowadays, musical artisanship is so ill distributed, performers so ill paid and the necessity of study so little understood, that _economy of time_ should be reckoned among the most imperative requisites of the orchestral conductor's art.
Let us now see what constitutes the mechanical part of this art.
The power of _beating the time_, without demanding very high musical attainments, is nevertheless sufficiently difficult to secure; and very few persons really possess it. The signs that the conductor should make--although generally very simple--nevertheless become complicated under certain circumstances, by the division and even the subdivision of the time of the bar.
The conductor is, above all, bound to possess a clear idea of the principal points and character of the work of which he is about to superintend the performance or study; in order that he may, without hesitation or mistake, at once determine the time of each movement desired by the composer. If he has not had the opportunity of receiving his instructions directly from the composer, or if the _times_ have not been transmitted to him by tradition, he must have recourse to the indications of the metronome, and study them well; the majority of composers, nowadays, taking the precaution to write them at the beginning, and in the course, of their pieces. I do not mean to say by this that it is necessary to imitate the mathematical regularity of the metronome, all music so performed would become of freezing stiffness, and I even doubt whether it would be possible to observe so flat a uniformity during a certain number of bars. But the metronome is none the less excellent to consult in order to know the original time, and its chief alterations.