ANY attempt to make a general history of music which will be a useful synthesis of data must have what we call continuity. When a presentation is criticized for lacking continuity, reference is usually made to the need for unity, coherence, and relevance of the detail to the whole. But the word continuity, when applied to the subject itself, is capable of various interpretations. And it is in defense of these interpretations that philosophies of music history have been formulated, in order to see the subject, if not as a whole, at least in its broadest aspects. Hence the term has far more significance than that which is usually attached to it in ordinary usage.
Roughly speaking, there are two main interpretations of continuity, the static and the dynamic. The static notion is that of a continuous series in a system of classification. The continuous, in this case, is something to be observed and studied in a fixed hierarchical scale, the members of which are so disposed as to shade by imperceptible degrees into those "above" and "below." This concept, that of the great Chain of Being,1 was at the basis of Père Mersenne Harmonie universelle (see Chapter 1) and of all the early treatises which emphasized the medieval classifications, divisions, and genera of music. Music is the only one of the fine arts which has been tied up with the concept of the scale. The tonal scale, therefore, being demonstrable with mathematics, was considered as a worthy subject of university study throughout the Middle Ages. But as Mersenne stated in 1627, and many still believe today, music was always "a part of mathematics." Now as long as music was or is studied mathematically, no history of music is possible. And no history was possible as long as men like Bontempi , Brossard , Malcolm , Grassineau , and Martini  were primarily interested in the classification of modes and genera (see Chapters 2, 3).____________________
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Publication information: Book title: Philosophies of Music History. Contributors: Warren Dwight Allen - Author. Publisher: American Book Company. Place of publication: New York. Publication year: 1939. Page number: 177.