168 THE NATURE OF MUSIC 



The subrhythm, the written form of which is the 

 measure, is named by the number and length of its 

 periods, therefore by its measure or metre. The sub- 

 rhythmic period is a beat of the measure. The 

 measure of subrhythms may be simple dual or triple, 

 compound dual or triple, mixed dual or mixed triple, 

 that is to say, the measure may contain 2 or 3 or 4 or 5 

 or 6 or 7 beats. The measure of five beats is mixed 

 dual because 5 is divisible into two parts, namely, 



2 + 3 or 3 + 2. The measure of 7 beats is mixed 

 triple because 7 is divisible into three parts, namely, 



3 + 2 + 2, 2 + 3 + 2, or 2 + 2+ 3. The length 

 of a subrhythmic period is named by that of the beat 

 of a measure and may be a I or J or ^ or I^ ; it may 



also be a 1 , I , JJn or j^. Hence the various 



indices of the measure of subrhythms as |, |, |, |, and 

 so on. The above dotted notes are suggested as 

 measure units and may be marked in the measure- 

 index by a corresponding dot after the number 

 indicating the unit as 1. instead of %, I instead of 

 I, I instead of |, |, instead of |, I, instead of ^^, etc. 

 All this but suggests the possibilities of diverse sub- 

 rhythmic forms, while those of the subdivisions and 

 expansions of those subrhythms must needs be left 

 to the suggestion and imagination of readers and 

 composers. 



Music has another resource for variety of rhythms 

 in another mode of division peculiar to itself. I allude 

 to the division of a unit into three parts or triplets as 



a . . 3 



G> into p p p , p into m f 9y m into # ^ # , and so 



