70 THE NATURE OF MUSIC 



mony; second, to the persistent and futile attempts to 

 base the theory of music on physical acoustics. There 

 are three evolutionary chapters of harmony which may 

 be provisionally indicated here. 



1. Homophonic Harmony. This is original har- 

 mony in one voice, which is the inherent harmony of 

 single melodies. By single melodies I mean all music 

 in one voice. This chapter represents the primary 

 age of music. 



2. Polyphonic Harmony. This is the inherent 

 harmony of combined melodies, that is, of two, three 

 or more coincident melodies. This chapter may also 

 be called contrapuntal harmony and constitutes 

 music's middle age. 



3. Chord-harmony. This, the only form thus far 

 recognized, is the supporting and accompanying har- 

 mony of single and combined melodies. This chapter 

 represents music's modern age. 



These three chapters and corresponding ages over- 

 lap; they mark a psychological advance from simple 

 to complex and from the indefinite to the definite ; they 

 correspond to the three psychological stages of music's 

 childhood, adolescence and maturity. The golden 

 thread by which all these forms of harmony are con- 

 nected in evolution has preserved only what was favor- 

 able and useful, so that in modern music all three are 

 employed in composition. The distinction here under 

 consideration may now be carried a step farther. 



Original harmony (one voice always understood) is 

 natural harmony by natural selection. Chord-har- 

 mony is personal harmony by personal selection. The 

 forms of original harmony select, assert and present 



