DISSONANCE AND CONSONANCE 71 



themselves ; in any single melody they are identical in 

 all of us, they are completely free from personal selec- 

 tion and therefore from the personal equation. Con- 

 cisely stated, personal selection cannot enter into 

 original harmony, in which the forms are uniformly 

 the same. In chord-harmony, on the other hand, we 

 are compelled to make a personal selection not only of 

 this or that series of specific constituent chords, but also 

 of the number of voices to be employed. Briefly, a 

 melody may be chorded in many ways while the origi- 

 nal harmony of a melody is uniformly the same. Thus 

 it is clear that the forms of original harmony are im- 

 mutable since they cannot be changed except by add- 

 ing other voices or chords. But the moment we do 

 this, two things happen simultaneously : first, the har- 

 mony is no longer in one voice; second, personal 

 selection usurps the place of natural selection in that 

 we add our own thought, and thus transform some- 

 thing that was universal into something that is per- 

 sonal. Hence the distinctions between natural and 

 personal harmony, between natural and personal 

 selection. The examples shown on page 72 illustrate 

 these distinctions and will suggest others. 



The common and immutable forms at a) are due to 

 natural selection, while the forms in all the subsequent 

 examples are due to personal selection. Concisely 

 stated, everything in more than one voice is personal. 

 The harmonic numbers in examples 6), c), d) and 

 e) agree with those in example a), w^hereby it is shown 

 that the chord-forms of personal selection may repro- 

 duce and elaborate the original forms of natural selec- 

 tion in a variety of ways. Original harmony is there- 



