By this time the idea of the improvement of voice culture was very generally held. García’s invention was hailed as the beginning of a new era in vocal instruction. It was coming also to be generally felt that the only way in which the scientific knowledge of the voice could be utilized in instruction would be by having the student of singing cause his vocal organs to operate in the manner that science had shown to be correct. While no one at that time stated this principle in definite terms, it was generally assumed as a matter of course. Within the twenty years following García’s invention the doctrine of the scientific management of the voice had been almost universally adopted. Against this tacit conviction in favor of the necessity of direct vocal management the instinctive methods of the old masters could make no stand. The old method gradually disappeared and the doctrine implied in the empirical system--that the voice needs no guidance other than that furnished by the ear--found no defenders. Since 1875 the belief in the necessity of consciously governing the vocal organs has been the dominating idea of vocal students and teachers throughout the world. [Illustration: Manuel García] _From a sketch from life by Pauline Viardot._ Of importance only second to García’s study of the vocal cord action was Helmholtz’s analysis of the acoustic laws of resonance, especially as they apply to tone and vowel formation. Merkel’s _Der Kehlkopf_ (1873) is the standard work on the operations of the larynx. Dr. Louis Mandl, in _Die Gesundheitslehre der Stimme_ (1876), first announced the principle of breath control. A vast number of other investigators have contributed to the subject and it is safe to say that the vocal action has been studied from every conceivable point of view. It is, however, not necessary here to trace the development of vocal science and to record the work of each student who has made original contributions to the common fund of knowledge. II In our first chapter the generally accepted theories regarding the operations of the vocal mechanism were outlined, and the same plan will be followed in describing the scientific methods of instruction most widely adopted. Modern methods of voice culture have indeed never been standardized. While teachers generally have adopted very nearly the same course, there is a wide diversity of opinion and practice to be found concerning each one of the topics of vocal science. Almost every one of these topics has indeed been the subject of controversy. Yet within recent years the leading authorities have come into fair accord in their application of the various principles. We shall therefore describe the method which has in its favor a consensus of opinion on the part of the best recognized teachers, without offering any statement as to its soundness or adequacy.