73. Summary of the Century.—The most salient external feature of the 16th century is the sudden expansion in magnitude of the world of music. Composers of importance now number some hundreds—almost as many as in the 17th century—and they are scattered through all the leading countries. Their known works count up into the thousands, chiefly designed for the church, but with a goodly proportion of secular compositions as well. The forms adopted are often extended and complex, so that into many single works went a large amount of effort and skill. In mere bulk of composition, then, the century is marked by an outburst of extraordinary artistic abundance.
But other features command attention. The period was instinct with the spirit of enterprise. Musicians were not content to go on doing the like of what had been done, but must needs strike out new paths. Even those wedded to the old lines of ritual composition usually supplemented or modified the old methods, and the few ultra-conservatives were unable to hold a following. The area of strict counterpoint, for example, was widened in various ways—by increasing the vocal forces and gathering them in contrasted choirs, by cunningly developing new beauties of close imitation (even by novel applications of the pure canon), by introducing more frequent harmonic passages as a foil for polyphony, by heightening the expressiveness of individual voice-parts and playing them off against each other more effectively, by reaching out after revolutionary extensions of the modes through chromatic tones, by experimenting with alternating tonalities or modulations, and by adopting into serious writing rhythmic and accentual refinements from secular sources.
The practice of what was called 'musica ficta' reached its climax
in this century. This was an instinctive recognition that chromatic
modifications of the modes were not only permissible but necessary
in certain situations, both for the better forming of the melodic
phrases and for the smoother articulation of the harmonic drift. At
first the insertion of irregular semitones was left to the singers'
discretion without written mark, but ultimately the necessary
sharps or flats were written above or in the staff. It is impossible
to tell how early or how far this license was applied before 1500,
but from that date it became the subject of formal rules,
especially in the formation of final or other cadences, in final
chords (making them regularly major), in cases where the tritone or
other objectionable intervals
