( 2073 ) 
This Mathematical fixing of the Frets enables every 
Praftitioner, who ftops clofe to them, to give the Pro- 
portions of the Notes in a greater exaftnefs, than can be 
done upon the Bafs^Violin or Violin itfelf: fiecc they 
may be fet forth more perfedly by a pair of Compaffes 
dividing a line, than the niceft Ear can direft. 
Though the Frets for the feveral Strings do not ftand in 
a ftrait line, and the places are alfo tliifted in different 
Keys, yet the Ear naturally direfts the Fingers to them : 
infomuch that thofe perfons, who have all their lives time 
been accuftom'd to ftopupon Frets that go quite crofsthe 
Finger-boards of their Inftruments, do with very little 
praftice fall right upon thefe* Such is the power of a 
Mufical Genius, as may be undeniably proved by thofe 
that play upon the Violin 5 who, when they change the 
Key, fall upon the right Stops, tho* they have no vifible/ 
direftion where to ftop, nor time to alter, by the 'Ear^ 
the Note they fir ft pitched upon* 
By this Standard of Regular Proportions may the Voice 
be formed to fing the pureft Notes 5 they are all the fame 
in Vocal and Inftrumental Mufick 3 if then the Inftrument 
which governs the Voice be perfe&, the Ear will of necef^ 
fity bring it to perfeftion. It is a great pity that a good 
natural Voice ftiould be taught to fing out of Tune, as it 
muft do, if it be guided by animperfeftlnfirument 5 and 
this may be the reafon why fofew attain to that melody, 
which isfo much valued 3 but fince we now know where» 
in perfeftion lies, a eonftant praftice will come to the at» 
tainment of it. The dividing Wholes into Chromatick 
Hemitones is very nec^ffary, but very difficult for the Voice 
tp be broken to : If it karns from an Inftrument whofe 
whole Notes and whofe half Notes are fuppofed to be e- 
qual, the found mult needs be very uncertain and unbar- 
monicaU whereas the proportions t*u)y fixed, wcu'd bring 
it to a perteftion in the niceft and moft charming part of 
Mufick. 
The 
