Final answer:
The system of music used before the Renaissance era was known as modal music. Modal music, with its scale patterns, gradually transformed into the system of tonality towards the end of the Renaissance, as composers began utilizing more perfect intervals like fifths.
Step-by-step explanation:
Before the Renaissance era, the system of music that was primarily used is known as modal music. This system, which precedes the more modern system of tonality, was characterized by modes, which are scale patterns that were the basis of Medieval and Renaissance music. During the late Renaissance period, these modal characteristics began to transform with the increased use of perfect intervals like fifths, which led to the development of tonality. This shift towards tonality became a defining trait in subsequent styles and eras of Western music, such as the Baroque period. Meanwhile, important theoretical advances—such as in rhythm and polyphony—took place in the Medieval period and had long-lasting impacts. The use of polyphony expanded during the Renaissance with more complex arrangements and the use of larger ensembles, which was a deviation from the primarily monophonic Gregorian chant of the earlier Medieval period.