Mem and Zin is a classic tale of traditional Kurdish storytelling, passed down through oral tradition for centuries, but also written down in 1692 by the Kurdish poet Ahmad Khani. In the process of fixing and recording the story, it's quite possible that Khani included some elements which are recognisably "his", rather than simply recording the tale as it was told orally. But some elements, such as the instructions to a "cupbearer", still seem like something out of oral tradition.
How much was changed, either in form or content, between the oral Mem and Zin and Khani's written version? Has anyone made a study of the oral forms to be able to do a careful comparison?