66 On RYTHMIC JL MEASURES. 



dovibtedly liflen with more fatisfadtion when we can perceive 

 the meafure from the real accent and expreffion of the notes, 

 than when we mull be afTifted by the continual repetition of un- 

 mufical founds. 



Such then feem to be the nature, the extent and the man- 

 ner of operation of what may be called our rythmical powers, 

 or thofe powers by which we afcertain and perceive the propor- 

 tional magnitudes of fmall intervals of time, when thefe are 

 marked out by motion, or by fucceffive founds. And froni 

 what has been faid, we eafily fee what a prodigious variety may 

 be introduced into mufical rythin, from the great range of long 

 and Ihort founds which may be occafionally employed, and 

 which may be difpofed and combined in a number of different 

 ways almoft infinite, without perplexing the hearer, or hinder- 

 ing him from readily and accurately feeling the proportional; 

 duration of each. 



In the foregoing account of thefe powers, I have frequently 

 fpoken of fingle Intervals or units of time. It may be proper,, 

 in this place, to explain a little more fully what I underftood 

 by thefe terms. It will readily occur to every one, that I did 

 not mean to exprefs by them a certain invariable portion of ab- 

 folute duration. Thefe units, like units in all other fubjeds, 

 are indeterminate and relative magnitudes. They mark fome- 

 times a greater, and at other times a lefs portion of abfolute 

 duration. The fame portion of abfolute time will, upon diffe- 

 rent occafions, be confidered as an unit, as a multiple and as a 

 part. Every one, however, who has been converfant in mufic, 

 experiences, that when he performs, or when he hears and goes- 

 along with a piece of mufic, there are certain notes which he 

 uniformly confiders as fingle durations, of which all the longer 

 notes that occur are aggregates, and the fliorter notes are parts. 

 He may therefore be very properly faid to have all this while 

 the idea of an unity of time. Although thefe units of time 

 differ confiderably in their abfolute duration in different move- 

 ments,. 



