CHORDS, or Coans, in music, are strings,by the vibrations of which the sen sation of sound is excited, and by the di visions of which the several degrees of tune are determined.
The of musical instruments are ordinarily made of catgut; though some are made of brass or iron wire, as those of harpsichords, spinnets, &c. Chords of gold-wire in harpsichords would yield a sound almost twice as strong as those of brass ; and those of steel a feebler sound than those of brass, as being both less heavy and less ductile.
The rules for dividing chords, so as to constitute any given interval, are as fol low : to assign such part of a chord A B as shall constitute any concord ; for example, a fifth, or any other interval, with the whole chord : divide the line A B into as many parts as the greatest number of the interval has units ; thus the fifth being 2 :3, the line is divided 'nto C three parts : I of these take as many as the lesser number 2 = A C, then is A C the part sought; that is, two lines whose lengths are to each other as A B to A C, make a fifth. Hence, if it be required to
find several different sections of the line A B, for instance such as shall be octave, fifth or third greater; reduce the given ratios 1 : 2, 2: 3, and 4 : 5 to one funda mental,the series becomes 30 : 24, 20: 15, the fundamental is 30, and the sections sought are 24 the third greater, 20 the fifth, and 15 the octave.
To divide a chord A B in the most simple manner, so as to exhibit all the original concords. Divide the line into two equal parts at C, and subdivide the part C D into equal parts at D, and again the part C D into equal parts at E.
C E D