39<S rOPTLAR LECTURES AND ADDRESSES. 



period of the harmony ; a second, half that of the 

 harmony ; a third, one-third that of the harmony, 

 and so on ; in other words, we may regard the 

 harmony as compounded of these simple tones. 



Practically, in musical language the term har- 

 mony is not applied when the tone of the main 

 period predominates in the sensory impression, 

 and in this case the sound is simply called a note ; 

 its pitch is reckoned according to the main period ; 

 and the effect of the other tones, now called over- 

 tones, which enter into its composition, are merely 

 felt as giving it its character or quality of sound. 

 Thus the name harmony is in musical practice 

 restricted to cases in which there is cither no tone 

 of the main or fundamental period, or not enough 

 to produce a predominating impression ; and a 

 sound compounded of two, three, four, or more 

 simple tones, having commensurable periods, is 

 heard. In ordinary musical language a harmony 

 is not regarded as having any one pitch, but is 

 thought of as compounded of its known constitu- 

 ents. The true period of the harmony is, however, 

 in every case the least common multiple of llic 



