A series of topics included in modern methods is now to be considered, different in scope from the strictly mechanical features of tone-production so far described. It must be apparent to the reader that the present understanding of the muscular processes of singing is not sufficient to furnish a complete method of instruction. This fact is thoroughly appreciated by the teachers of singing. Almost without exception they seek to supplement the mechanical doctrines by instruction of an entirely different character. The subjects included in this form of instruction are of several classes. They comprise the manner of emission of the tone, the traditional precepts of the old Italian school, the singer's sensations, and the use of certain vowels and consonants for special purposes. _Emission and Forward Placing_ Of all the traditional precepts, the one most frequently cited in theoretical treatises on the voice is, "Place the tone forward." For this precept it is generally believed that a satisfactory explanation has been found in the accepted doctrine of tone emission. The characteristic effect of perfect singing known as the "forward tone" is thoroughly well known to every lover of singing. In some peculiar way the tone, when perfectly produced, seems to issue directly from the singer's mouth. When we listen to a poorly trained and faulty singer the tones seem to be caught somewhere in the singer's throat. We feel instinctively that if the singer could only lift the voice off the throat, and bring it forward in the mouth, the tones would be greatly improved in character. It is commonly believed that the old masters knew some way in which this can be done. Just what means they used for this purpose is not known. But the accepted scientific interpretation of the "forward tone" precept is held by vocal theorists to render the subject perfectly clear.