Who has the most influence over each of these artistic genres?
Who likes the changes and who doesn't?
Who benefits from these changes?
Do gender roles alter in these areas?
Why so or why not?
Please allow some of my ideas to help within this large topical area:
First of all, in terms of who has the most influence over each of these artistic genres, you might assert that art and music were vital parts of medieval religious life, so the church was influential in these areas. Research shows that "Singing without instrumental accompaniment was an essential part of church services. Monks and priests chanted the divine offices and the mass daily" (http://www.learner.org/interactives/middleages/artsentr.html).
In the area of drama, you might talk about how medieval drama also came from "the liturgy, beginning in about the eleventh century. Some of the topics were from the Old Testament (Noah and the flood, Jonah and the whale, Daniel in the lion's den) and others were stories about the birth and death of Christ" (http://www.learner.org/interactives/middleages/artsentr.html). In other words, you might look at how artists during the Middle Ages, in general, were influenced strongly in aims to glorify God.
As you talk specifically about the visual arts, it ...
Middle Ages and artistic contexts are briefly discussed.