Vocal theorists generally treat the subject of attack as connected in some way with registers and laryngeal action. But as no rule has ever been formulated for the mechanical management of the laryngeal action, it necessarily follows that no intelligible directions are ever given to the student for preparing to start the laryngeal action correctly. Three possible ways of attacking a tone are generally recognized. These are described by Albert B. Bach, in _The Principles of Singing_, second edition, London, 1897. They are, first, the stroke of the glottis. (This is advocated by Garcia in most of his published works, although the testimony of many of his pupils, notably Mme. Marchesi, is that Garcia used the glottic stroke very little in actual instruction.) Second, the aspirate (_h_ as in _have_), which is generally condemned. Third, the approximation of the vocal cords at the precise instant the breath blast strikes them. This latter mode of attack is advocated by Browne and Behnke, who call it the "slide of the glottis." It must be observed that neither the stroke nor the slide of the glottis can be shown to have any influence in causing the laryngeal muscles to adopt any particular mode of adjustment. Turning to practical methods of instruction, little connection can be traced between the theories of attack and the occasional directions usually given for starting the tone. The subject of attack is seldom assigned to any particular period in the course of study. Many teachers ignore the matter altogether. Others devote a few minutes now and then to drilling a pupil in the stroke of the glottis, without attaching much importance to the subject. (The position assigned to this mode of attack by the "breath-band" theorists has already been mentioned.) On the whole, the matter of attack is usually treated rather loosely. The pupil is occasionally interrupted in singing a phrase, and told to "attack the tone better." Needless to say, this form of instruction is in no sense scientific. CHAPTER IV RESONANCE In order to understand fully the position in Vocal Science assigned to the doctrine of resonance, it is necessary to trace the origin and the development of this doctrine. The old Italian masters naturally knew nothing whatever of resonance, nor of any other topic of acoustics. Yet the accepted theories of resonance in its relation to the voice are directly based on a set of empirical observations made by the old masters. The facts which they noted are now a matter of common knowledge. In singing low notes a sensation of trembling or vibration is felt in the upper chest; high notes are accompanied by a similar sensation in the head. How these sensations of vibration came to be made the basis of the theories of vocal resonance, and of registers as well, is an interesting bit of vocal history.