CHAPTER XXVIII 



MUSICAL INSTRUMENTS 



265. Musical instruments maybe divided into three groups 

 according to the different ways in which their tones are 

 produced : 



First. The stringed instruments in which sound is pro- 

 duced by the vibration of stretched strings, as in the piano, 

 violin, guitar, mandolin. 



Second. The wind instruments in which sound is produced 

 by the vibrations of definite columns of air, as in the organ, 

 flute, cornet, trombone. 



Third. The percussion instruments, in which sound is 

 produced by the motion of stretched membranes, as in the 

 drum, or by the motion of metal disks, as in the tambourines 

 and cymbals. 



266. Stringed Instruments. If the lid of a piano is opened, 

 numerous wires are seen within ; some long, some short, some 

 coarse, some fine. Beneath each wire is a small felt ham- 

 mer connected with the keys in such a way that when a key 

 is pressed, a string is struck by a hammer and is thrown into 

 vibration, thereby producing a tone. 



If we press the lowest key, that is, the key giving forth the 

 lowest pitch, we see that the longest wire is struck and set 

 into vibration ; if we press the highest key, that is, the key 

 giving the highest pitch, we see that the shortest wire is 

 struck. In addition, it is seen that the short wires which 



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