Sita Sings the Blues is based on the Hindu epic The Ramayana. Sita is a goddess separated from her beloved Lord and husband Rama.
The Ramayana is attributed Valmiki, who was drawing upon an earlier oral tradition. According to Valmiki, Rama dictated to him the story, he was merely the scribe who wrote it in Sanskrit.
The tradition then, is we draw upon what went before. That is until we enclosed the intellectual commons, and intellectual property rights reared its ugly head, having looted the commons, we then sell it back, packaged as entertainment.
To resolve all the copyright issues associated with Sita Sings the Blues, Nina went $70,000 into debt. It is important to emphasise, this was just to clear restrictive copyright issues, it was not the budget for making the film. The copyright issues took a year to resolve.
In Dark Mountain Vol 5, Strange Children written by Akshay Ahuja tells one of the stories from the other great India epic Mahabharata.