For the encouragement to my little work which renders a third issue necessary, I take this opportunity of expressing my sincere thanks.

I have ceased to call it a Theory founded on the Tempered Scale for two reasons: ist, Because I believe it will be found perfectly applicable to the system of just intonation; 2nd, Because the attitude of scientific men to modern chromatic music has ceased to be that of hostility, inasmuch as they see that their system will never be adopted as long as it threatens the existence of a single masterpiece in musical literature, while, on the other hand, it will be universally accepted when it renders such works capable of more perfect performance.

As I heartily wish for this consummation, it is unnecessary for me to reprint the two polemical prefaces to former editions.