Final answer:
In the medieval music world, the innovations of sheet music and polyphony were significant as they allowed for distribution of standard music and introduced a complex musical texture with multiple melodic voices.
Step-by-step explanation:
The new innovations that became common in the medieval music world primarily include sheet music and polyphony. Sheet music allowed for the widespread distribution and standardization of music, helping to disseminate musical compositions more efficiently and accurately. Polyphony, a type of musical texture involving multiple independent melodic voices, became prevalent by the late thirteenth and early fourteenth centuries, marking a significant departure from the previously monophonic liturgical music like Gregorian chant, and leading towards the richer and more complex musical structures of the Renaissance.