The influence of the same stream of air increases in proportion as the breadth of the vibrating ligaments decreases. The tones of the falsetto and head registers, therefore, require far less breath than those of the chest register. The less the quantity of breath expended in these tones, and the easier and more quickly they are produced, the clearer and fuller do they sound. The mechanism of the head tones especially is, as we have seen, so delicate that only a slight excess of breath calls forth the inharmonic over-tones which render the tone sharp and unmusical. In wind instruments the tone can be forced upwards by a greater pressure of air; that is, by more powerful blowing, which appears to be practicable also in those instruments in whose peculiar timbre the highest inharmonic over-tones overpower the others.[13] Together with the skill and unintermitted attention which this part of instruction in singing requires of the teacher, there are here yet other and peculiar difficulties which he has to meet. In opposition to the earlier and more correct view, it is no longer beauty of tone, but strength of tone, which is considered the chief excellence of a voice. Accustomed to seek the beauty of the voice in its strength, it is attempted, before the time of instruction begins, to sing as strongly as possible from a full chest with the greatest expulsion of breath. Thence it follows, in the superficial way in which the study of the art of singing is at present conducted, that nothing more is commonly required of a teacher than that he should be able to drill his pupil in some pieces of tolerably well conceived vocal music, which the latter must sing as soon as possible in company. A perfect culture of the voice is scarcely any longer expected of an artist. People with a very scanty musical education and voices very poorly trained are regarded as artists if they execute their parts with expression, and trick them out with those clap-traps which never fail to command the applause of the ordinary public. A conscientious teacher has, therefore, universal opinion against him when he demands a longer time for the education of a voice, and requires of his pupils that they shall practice singing only piano as long as it is necessary. THE CORRECT TOUCH OF THE VOICE (TONANSATZ)[14]