During the time of the Franco-Flemish school in Renaissance music, use of the French notation system spread throughout Europe. This period brought the replacement of black with white notation. It also brought a further slowing of the duration of the larger note values, while introducing even more new small ones (fusa, semifusa, etc.). Toward the end of this period, the original rules of perfection and imperfection became obsolescent, as did the use of ligatures. During the 17th century, the system of mensuration signs and proportions gradually developed into the modern time signatures, and new notation devices for time measurements, such as bar lines and ties, were introduced, ultimately leading toward the modern notation system.
