The answer is ethnocentrism.
Music was a huge theme for The Harlem writers back then
That depends. Who's asking?
The plan is, of course, I actually organized by nature in to continents and oceans and one way of representing this is by the globe displaying a spherical World imitating the planet with all the displayed continents and with the oceans and wide islands interfering and with all the names shown by the oceans in continents.