Joel and Ethan Coen loosely based O Brother, Where Art Thou? on Homer's epic poem, Odyssey. The title comes from the film Sullivan's Travels where the protagonist is a director trying to make a movie called O Brother, Where Art Thou? The Coen Brothers used the Great Depression as the backdrop for their tale, and set to work reinterpreting a classic myth in the context of a fabled American South.
Interestingly enough, the Coen Brothers had never read Homer's poem when they began working on their film. They had learned of the story through pop-culture and references, but they never actually read the poem. This added to their artistic license, and they created a completely new tale while borrowing elements from other sources, creating an eclectic aesthetic and narrative world.
Part of envisioning a mythic South was taking aesthetic liberties. The Coen Brothers closely collaborated with cinematographer Roger Deakins to bring a specific look of the dry Mississippi delta to the picture. They used digital color correction in order to get the palette they wanted, as the landscape was actually very green during the time of filming. Additionally, the directors enlisted the help of musician and producer T. Bone Burnett to create the soundtrack for the film. The music was a major component of the narrative arc, and the soundtrack was written and recorded before the film began shooting. Indeed, the soundtrack was a major part of the success of the film, adding depth to the journey for the main characters.
