Hmm. Let me rephrase it:
"To my mind, 'deep' acts as a complement, and tells us something about the subject at the end of the process; whereas 'deeply' tells us something about the process itself."
"Wide" in this context is presumably meant to relate to "breadth of emotion, etc".
The problem with the example is that it expresses a metaphor with only one term. We know that X goes deep and wide, and that it goes deeper and wider than another X; and we know that one X is like music, and the other X is like literature.
But what goes deep and wide? Some kind of surgical instrument, maybe?
What do you picture?
MrP