142 THE NATURE OF MUSIC 



Regnant I being the first harmony, do being the root 

 of this harmony and the original meloharmonie point 

 of repose which we call the Tonic, it follows that do 

 is the original centre of the tone-region, as follows : — 



sol — la — ti ^ Do — re — mi ^ f a 



V I IV 



Here the seven diatonics form a scale of two 

 conjunct tetrachords. The Tonic do is the common 

 tone and common centre of the two. A tetrachord 

 is a scale of four tones. The above dashes ( — ) and 

 curves (w) indicate respectively whole steps and 

 half steps, and show that the two above tetrachords 



have the same form, namely, ^-^. This scale of 



seven tones and conjunct tetrachords I have named 

 the septonate.* The septonate is the nucleus of the 

 tone-region. What evidence is there that do the 

 Tonic is the original centre of the tone-region ? The 

 incontrovertible evidence is adduced from harmony 

 briefly as follows: — 



The cadence of V rises or resolves upward into I; 

 the cadence of IV resolves downward into I: ergo, I 

 lies between V and IV. This septonal nucleus of the 

 tone-region besides being the index of meloharmonie 

 resolution is also the index of progression. For 

 example, from V to IV progress upward, from IV to 

 V progress downward. What is true of these har- 

 monies is true of the corresponding chords. From 

 the intuitive feeling of these one-voice self-assertive 

 resolutions and progressions the rules for treating the 

 corresponding chords in corresponding relations and 



