An explanation of this is given by Maspero, who says: "The human voice is pre-eminently a magical instrument, without which none of the highest operations of art can be successful: each of its utterances is carried into the region of the invisible and there releases forces of which the general run of people have no idea, either as to their existence or their manifold action. Without doubt, the real value of an evocation lies in its text, or the sequence of the words of which it is composed, and the tone in which it is enunciated. In order to be efficacious, the conjuration should be accompanied by chanting, either an incantation or a song. In order to produce the desired effect the sacramental melody must be chanted without the variation of a single modulation: one false note, one mistake in the measure, the introversion of any two of the sounds of which it is composed, and the intended effect is annulled. This is the reason why all who recite a prayer or formula intended to force the gods to perform certain acts must be of true voice. The result of their effort, whether successful or unsuccessful, will depend upon the exactness of their voice. It was the voice, therefore, which played the most important part in the oblation, in the prayer of definite request, and in the evocation--in a word, in every instance where man sought to seize hold of the god." Apart from a "true voice" the words were merely dead sounds. The character of the voice plays an important part in many religions. The Vedas contain in them many invocations and hymns which no uninitiated Brahman can recite: it is only the initiate who knows their true properties and how to put them into use. Some of the hymns of the _Rig-Veda_, when anagrammatically arranged, will yield all the secret invocations which were used for magical purposes in the Brahmanical ceremonies. Some Parsees pay much attention to what is called _dzád dwá_ or "free voice." It is recorded in Moslem tradition that a revelation came to the venerated Arabian prophet resembling "the tone of a bell." The effects which low, monotonous chanting produce on nervous people and children are well known. Even animals and serpents are amenable to the influence of sound.