Take EDM for example; it's a combination of words and sounds all cramed together to create a piece of music, most of the time it has no official reason or back story but is simply made to be enjoyed. This concept is the same with Jazz music. When jazz was invented there was no definitive reason or way to play it, you just grabbed an instrument and started playing whatever cords and rhythms you thought sounded nice.
Answer:
Casting Manager or Casting Director
Explanation:
I can't find the difference between the two, but it's definitely not the director or the producer. I'm leaning more towards casting director.
