CHAP, iv.] WIND INSTRUMENTS. 167 



CHAPTER IV. 



WIND INSTRUMENTS. 



TO distinguish clearly musical instruments having their sounds 

 produced by the vibrations of strings from those called Wind 

 Instruments, we must not only consider the method of the produc- 

 tion of sound, but also the nature of the body the vibrations of 

 which determine the musical qualities of the sound produced, that 

 is to say, its pitch, intensity, and tone. 



We have seen that generally in stringed instruments the sounding 

 body is not only composed of vibrating strings, arranged on a frame, 

 but of a wooden or metal box or case, and the mass of air contained 

 in it. Now the string alone, by its thickness, length, tension, and 

 the substance of which it is formed, determines the musical pitch 

 of the note and partly its tone. The body and the air which also 

 enter into vibration when the string is struck, plucked, or bowed, 

 serve to strengthen the sound produced, without modifying its 

 pitch; they have also a great influence on the tone, by giving pre- 

 ponderance to one or another of the harmonics of the fundamental 

 note ; but they have no appreciable influence on the pitch. 



In wind instruments which we are now about to describe, the 

 sonorous body and vibrating mass is a column of air, with a form 

 varying with that of the case in which it is inclosed ; the variations 

 of dimension and form of this column cause the variations in the 

 musical pitch of the notes produced, and the sides of the tube only 

 serve to modify the sonorousness or intensity of these notes. 

 Solidity is the real desideratum in the walls of all pipes. The 

 way to produce the note is therefore very different from that em- 

 ployed for stringed instruments. It is the column of air which must 



