Anne, I realised as soon as I pressed send on my post above that you were referring to medieval non-musical story-telling and my link was to the performance of stories-in-song - so related, but not specifically what you're after. I'm very probably asking the obvious here, but I wonder if adept and long-time stroy-tellers such as Hugh Lupton, Taffy Thomas, Debs Newbold, etc. have looked into this.