Final answer:
A polyphonic form with three or four voices from the Renaissance era can refer to the motet or madrigal. These forms highlight the growing importance of harmonious thirds and the independence of vocal lines, marking a significant shift from the monophonic Medieval music tradition.
Step-by-step explanation:
The polyphonic form consisting of three or sometimes four voices is typically associated with genres such as the motet or the madrigal in the context of Renaissance music. Particularly in the Renaissance, the interval of the third became more important, changing the perception of harmony and consonance from the earlier Medieval practices where it was considered a dissonance. Polyphony emphasized the independence of each vocal line and was strongly present in sacred music, although it was used for secular songs too, as in the madrigal, where the two higher voices often imitated each other in a canon over a simpler instrumental accompaniment. It illustrates a paradigm shift from the monophonic texture of Gregorian chants to the intricate polyphonic structures.