Before undertaking this exhaustive analysis of the vocal action it is advisable to review in detail every method of instruction in singing now in vogue. This may seem a very difficult task. To the casual observer conditions in the vocal world appear truly chaotic. Almost every prominent teacher believes himself to possess a method peculiarly his own; it would not be easy to find two masters who agree on every point, practical as well as theoretical. But this confusion of methods is only on the surface. All teachers draw the materials of their methods from the same sources. An outline of the history of Voice Culture, including the rise of the old Italian school and the development of Vocal Science, will render the present situation in the vocal profession sufficiently clear. Part I of this work contains a review of modern methods. In Part II a critical analysis is offered of certain theories of the vocal action which receive much attention in practical instruction. Several of the accepted doctrines of Vocal Science, notably those of breath-control, chest and nasal resonance, and forward placing of the tone, are found on examination to contain serious fallacies. More important even than the specific errors involved in these doctrines, the basic principle of modern Voice Culture is also found to be false. All methods are based on the theory that the voice requires to be directly and consciously managed in the performance of its muscular operations. When tested by the psychological laws of muscular guidance, this theory of mechanical tone-production is found to be a complete error. Part III contains a summary of all present knowledge of the voice. First, the insight into the singer's vocal operations is considered, which the hearer obtains by attentive listening to the tones produced. This empirical knowledge, as it is generally called, indicates a state of unnecessary throat tension as the cause, or at any rate the accompaniment, of every faulty tone. Further, an outline is given of all scientific knowledge of the voice. The anatomy of the vocal organs, and the acoustic and mechanical principles of the vocal action, are briefly described. Finally, the psychological laws of tone-production are considered. It is seen that under normal conditions the voice instinctively obeys the commands of the ear.