124 THE NATURE OF MUSIC 



17. As defined on a previous page, a harmony 

 is diatonic when all its components are diatonics. 

 The test of the pure diatonic harmonies of melody, 

 in fact of all the harmonic forms and relations of 

 melody, lies in the common reports of original har- 

 mony in one voice. In one voice a diatonic in certain 

 relations generates a thread of harmony in which all 

 the concomitants are diatonics, while in certain 

 other relations the same diatonic generates a thread 

 of harmony among whose components there are 

 chromatics and even enharmonics mingling with 

 diatonics, as we shall see in the sequel. Here we are 

 concerned with pure diatonic harmonies. I, V, V^, 

 V9 and IV are diatonic harmonies and the only ones 

 in the Major mode. All forms of harmony are con- 

 sonances or dissonances. Each specific form of conso- 

 nance and dissonance had its genesis on a specific 

 tone in a specific relation, and each such original form 

 is a prototype. Once generated and differentiated 

 each prototype is reproduced and repeated on other 

 tones also in specific relations. The harmonies thus 

 far generated will serve as an illustration. I, V and 

 IV are major consonances : I is the prototype of this 

 specific form and it first arose on do 1; V and IV are 

 reproductions and replicates, the former arose on re 5, 

 the latter on la 3. Again, V^ and V9 are major dis- 

 sonances, and both are prototypes of their respective 

 forms of which all like forms are replicates. This 

 concludes the summary of the diatonic harmonies of 

 the Major mode. In the next chapter, the subject of 

 which is the origin of the Minor harmony and mode, 

 we shall encounter three other diatonic harmonies and 



