Final answer:
The minimum number of voices in a motet is typically three, reflecting the increased complexity and vocal range of Renaissance polyphonic music.
Step-by-step explanation:
The minimum number of voices included in a motet is typically three, but it can vary. During the early Renaissance, polyphony became increasingly elaborate and composers like Cyprien de Rore made use of the interval of the third, which was a shift from the Middle Ages where thirds were seen as dissonances. The evolution of vocal music during this period also saw an increase in vocal range, allowing for smoother combination of voices and less need for frequent crossing of parts.