There must be some definite reason for the failure of theoretical investigation to produce a satisfactory Science of Voice Culture. This cannot be due to any present lack of understanding of the vocal mechanism on the part of scientific students of the subject. The anatomy and physiology of the vocal organs have been exhaustively studied by a vast number of highly trained experts. So far as the muscular operations of tone-production are concerned, and the laws of acoustics bearing on the vocal action, no new discovery can well be expected. But in this very fact, the exhaustive attention paid to the mechanical operations of the voice, is seen the incompleteness of Vocal Science. Attention has been turned exclusively to the mechanical features of tone-production, and in consequence many important facts bearing on the voice have been overlooked. In spite of the general acceptance of the doctrines of Vocal Science, tone-production has not really been studied from the purely scientific standpoint. The use of the word "science" presupposes the careful observation and study of all facts and phenomena bearing in any way on the subject investigated. Viewed in this light, the scientific study of the voice is at once seen to be incomplete. True, the use of the voice is a muscular operation, and a knowledge of the muscular structure of the vocal organs is necessary to an understanding of the voice. But this knowledge alone is not sufficient. Like every other voluntary muscular operation, tone-production is subject to the psychological laws of control and guidance. Psychology is therefore of equal importance with anatomy and acoustics as an element of Vocal Science. There is also another line along which all previous investigation of the voice is singularly incomplete. An immense fund of information about the vocal action is obtained by attentive listening to voices, and in no other way. Yet this important element in Vocal Science is almost completely neglected. In order to arrive at an assured basis for the art of Voice Culture, it is necessary in the first place to apply the strictest rules of scientific investigation to the study of the voice. A definite plan must be adopted, to include every available source information. First, the insight into the operations of the voice, obtained by listening to voices, must be reviewed and analyzed. Second, the sciences of anatomy, mechanics, acoustics, and psychology must each contribute its share to the general fund of information. Third, from all the facts thus brought together the general laws of vocal control and management must be deduced.