Folk artists of the spoken word are generally not famous and do not receive recognition, in part because our society is naturally prejudiced on behalf of the written word. That's not to say there haven't been some "Shakespeares" among those who told wonderful stories. The great folklore archives are filled with eloquent tellings of folktales, which rival anything that has been printed. One could spend a lifetime (and be glad for it!) reading the material that is available in the Irish archives at the Department of Irish Folklore in Dublin. But the same would be true of the material in Copenhagen, Uppsala, or Reykjavik - and many other places. They document the words spoken by remarkable artists whose words would have passed with the storytellers had not diligent folklorists collected what they had to say.

With that in mind, we can consider, for a moment, a few printed documents. The "Ossian poems" by James Macpherson, which appeared in the 1760s, were supposed to be from an Iron Age oral tradition. It turned out Macpherson largely concocted the material, but not before it became quite the sensation. This was an early attempt to offer "high grade literature from oral tradition," but it serves to remind us that we must be careful about those who would pass off fraudulent material.

The Kalevala, the epic poem of Finland appeared in 1835 and stitches together material from oral tradition. It is highly regarded and comes close to what you seek - in printed form. It influenced Tolkien and continues to be a source of pride for the Finns. The "stitching together" was less violent than what Macpherson did, but the Kalevala is ultimately a step removed from oral tradition.

For something a little less high brow and truer to oral tradition, I always recommend Peig: The Autobiography of Peig Sayers of the Great Blasket Island. This humble recounting of the life of Peig Sayers (1873-1958), a great storyteller of the proportions of Shakespeare, offers a window into the world of oral tradition and how those who crafted the written world reached the level of high art - I believe the sort of thing you seek. But one must always remember that if genuine oral tradition is what one seeks, the word "humble" will always be important, and that's not a word that is easily applied to Shakespeare.

You might also be interested in the great West African epic of Sundiata (or variant spellings). It's the story of 13th century Malinke king Sundiata Keita who founded the Mali Empire. The poem--in all its versions, which continue to circulate orally today--is especially fascinating because it preserves, in some tellings, the tradition of storytelling and its importance to the Mande today. How "historical" or "accurate" for the Middle Ages is it? That is a question that scholars continue to debate and investigate.

An amazing blessing of studying Sundiata, as an Anglophone reader, from the point of view of oral tradition, is the availability of multiple, affordable English versions with roots in the performance of different griots.

Niane (translating Kouyate into French), Eng. trans. Pickett, Sundiata: An Epic of Old Mali is a prose version that is frequently read in early African history classes.

Penguin Classics published two verse versions in Suso and Kanute, trans. Innes, Sunjata.