MUSIC, &c. 



THE science of harmonical sounds; instrumen- 

 tal or vocal harmony. 



The Musical Signs. 



The seven musical signs, ut, re, mi, fa, sol, la, sa, 

 invented by the Benedictine monk Guido Aretino, 

 are the first syllables of some words contained in the 

 first strophe of a Latin hymn, composed in honour 

 of St. John the Baptist, which runs thus : 

 Ut queant laxis, ../-.Famuli tuorum 

 Mira, gestorum , > Zabiis reatum 

 Solve pollutis Saute Joannes. 



Resonare fibris 



Octaves and Concord. 



When two strings, whose length is as one to two, 

 vibrate together, it is obvious that the one vibrates 

 twice, while the other only vibrates once ; they will 

 coincide at the beginning of every alternate vibra- 

 tion, and their sounds will then accord. When the 

 strings are in this proportion, their coincidences are 

 more frequent than when their lengths are in any 

 other ratio, and hence it is that the octave is the 

 most perfect concord. 



If the lengths be two to three, which is the ratio 

 of the fifth, every third vibration of the one coincides 

 with every second of the other ; the coincidences are 

 consequently not so frequent as in the octaves, on 

 which account the concord is not so frequent. 



