Now, as in past times, the high falsetto for males, if good, the result of proper training, has the warrant of both art and sound physiology. In the use of registers, sensations are infallible guides. Of these, the most important are those associated with the organs of hearing, but those arising in the vocal organs are also valuable. Those only should expect to sing artistically, and to preserve their voices unimpaired for a long period, who wisely observe Nature's teachings in regard to registers. CHAPTER XII. FUNDAMENTAL PRINCIPLES UNDERLYING VOICE-PRODUCTION. It is highly important for the speaker or singer to realize early in his career that all forms of artistic expression can be carried out only through movements--muscular movements; in other words, technique or execution implies the use of neuro-muscular mechanisms. However beautiful the conception in the mind of the painter, it can only become an artistic thing when it assumes material form--when it is put on canvas. The most beautiful melody is no possession of the world while it is in the mind of the composer alone; till it is _expressed_, it is as good as non-existent. Even poetry can only affect us when it exists in the form of words produced by lip or pen. Between the glowing thought of the poet and the corresponding emotion produced in ourselves there must intervene some form of technique--_i.e._, some application of neuro-muscular action. This latter term is a convenient one, and has been already explained. It is a condensed expression for that use of the nervous and muscular systems that results in movements, simple or complex. Without nerve-cells and muscles movements are impossible, speaking generally, and for a willed or voluntary movement there must be something more, an idea or concept. Before one can make a movement resulting in a simple line or even dot on a piece of paper, he must have the idea of that line or dot in mind. In like manner, before one plays or sings a single note, he must have the idea of that note in mind; in other words, the idea is the antecedent to the movement, and absolutely essential. To have such an idea, memory is necessary. It is impossible to sing a tone after another, as an imitative effort, unless one has the power to retain that tone in memory for at least a brief period of time; and before this same tone can be reproduced on sight of it as represented by a written note, the memory of the sound to which it answers must first be recalled; and not only so, but other memories--indeed, memories of all the sensations associated with the bodily mechanism used in producing it.