Some stories are just too iconic to tell only once. So the Coen brothers thought when they wrote O Brother, Where Art Thou, an adaptation of the Greek epic The Odyssey. The classic story was too big to remain only in ancient Greece. It deserved a modern equivalent.
But simply transposing the story into a new setting wasn’t good enough. This is cheap adaptation. No, the Coen brothers understood that stories need to grow, adapt, evolve, an even change. They can begin with the source material, but unless something is added, it will not be a story that speaks to its time.
And so, that’s exactly what they did. Using the structure of The Odyssey and transposing it to the 1930s south, they began with something familiar in order to tell a new story.