A method of instruction in singing therefore consists primarily of a set of mechanical rules and directions for managing the voice, and secondarily of a series of exercises, both toneless and vocal, so designed that the student may directly apply in practising them the rules and directions for vocal management. It must not be understood however that the mechanical rules are applied only to the exercises specially designed for this purpose. These rules and directions are also intended to be applied to everything the student sings,--exercises, technical studies, and musical compositions. It will be recalled that the review of the topics of modern vocal instruction covered three distinct types of materials. First, the purely mechanical doctrines, commonly regarded as the only strictly scientific principles of Voice Culture. These are, the rules for the management of the breath, of the registers, of laryngeal action, and of the resonance cavities, and also the directions for attacking the tone, and for forward emission. The second class of materials is held by strict adherents of the scientific idea to be purely empirical; this class includes the traditional precepts of the old Italian school, and also all the topics of instruction based on the singer's sensations. A third class of materials is found in the attempts to interpret the empirical doctrines in the light of the scientific analysis of the vocal action. To enumerate and classify all the methods of instruction in vogue would be almost an impossibility. Absolutely no uniformity can be found on any topic. Even among the accepted doctrines of Vocal Science there are many controverted points. Five distinct schools of breathing are represented, two of breath-control. Of well worked-out systems of registers, at least twenty could be enumerated. Fully this number of theories are offered regarding the correct positions of the larynx, soft palate, and tongue. Two opposed theories are held as to nasal resonance. Further, the empirical doctrines are always stated so loosely that no real unanimity of view can be found on any one of them. Every vocal teacher selects the materials of instruction from these controverted doctrines, but neither rule nor reason determines what materials shall be embodied in any one method. There is no coherence whatever in the matter. Further, there is no agreement as to which topics of instruction are most important. One teacher may emphasize breath-control and support of tone as the foundations of the correct vocal action, another may give this position to nasal resonance and forward placing. Yet both these teachers may include in their methods about the same topics. The methods seem entirely different, only because each makes some one or two doctrines the most important. In short, it might almost be said that there are as many methods as teachers.