The great majority of teachers occupy a middle ground between the two types just described. Teachers of this class touch, more or less, on every topic of instruction, mechanical, empirical, and interpretive. Their application of most of the topics of instruction is not quite so mechanical as in the first type of method considered. The student's attention is always directed to the vocal organs, but the idea of direct muscular control is not so consistently put forward. As a rule, the attempt is made in the first stages of instruction to follow a systematic plan. Breathing, and perhaps breath-control, are first taught as muscular drills, and then applied on single tones. Attack is generally taken up next, then simple exercises in the medium register. Following this, the chest and head registers are placed, and the attention is turned to emission and resonance. But in most cases, when the pupil has covered three or four terms of twenty lessons each, all system is abandoned. The method from that time on is about of the type described as empirical. It must be remembered that this classification of methods is at best very crude. It would not be easy to pick out any one teacher who adheres consistently to any of the three forms of instruction described. All that can be said is that a teacher usually tends somewhat more to one type than to another. Further, the degree of prominence given to the idea of direct mechanical control of the voice does not classify a method quite satisfactorily. Without exception every teacher adheres to the prevailing idea, that the voice must be controlled and guided in some direct way,--that the singer "must do something" to cause the vocal organs to operate properly. All the materials of instruction, mechanical and empirical, are utilized for the sole purpose of enabling the student to learn how to "do this something." Several names are used by teachers to describe their methods. One professes to teach a "natural method," another the "pure Italian school of Bel Canto," a third the "old Italian method as illustrated by Vocal Science," a fourth the "strict scientific system of Voice Culture." No attention need be paid to these expressions, as they are seldom accurate descriptions. Vocal lessons are usually of thirty minutes' duration. Each student generally takes two such lessons every week, although in some cases three, four, or even more are taken. A description of a few typical lessons will show how the materials of instruction are practically utilized.