When the figure and ground are about equal in area an artist can create a __________, in which either color can be interpreted as lying on top of the other

Why is church music the only music from the Middle Ages that has been preserved in any significant amount?

What will be an ideal response?

Which of the following keeps sound that is being recorded from being too loud or too soft?

a. a balancer b. an AGC c. an X-Y d. a modulator