Theres a book about Ulysses by Stuart Gilbert.
He traces the origins of the big ballads to in the history of Dublin to the Vikings. Apparently the Vikings,when they had a knees up, had scary minstrels called Bareserks who would embark on an improvised ballad under the influence of strong drink. The performance could go on for several days and was punctuated with the minstrel killing members of the audience when performing particularly moving passages of his ballad.

So Beowolf, why not?.... But warn me in advance and I'll slip out for a pee,