Despite the need to improve on and further Horsley's work, he nevertheless does provide a helpful opportunity to think more largely about biblical studies and the concrete social functioning of the texts we analyze. This has always been one of the key strengths of Horsley's scholarship. So I thought I'd reproduce this helpful quote on the need for us to get past ourselves and appreciate Mark's gospel as, perhaps, a single performance of the Jesus tradition rather than a collection of previously independent short stories (novella, according to Dibelius).
What remains difficult even for those who recognize Mark as a sustained story, I think, and perhaps also for those of us who also recognize the interface of orality and writing, is to imagine the formation, the composition, of the whole (Gospel) story. Perhaps because we are so habituated to composition in/as writing we have particular difficulty imagining how a text of the length and complexity of Mark could have been composed other than in writing—even though many epics that are orally performed (and composed) are much longer and more complex in plotting than Mark and the other Gospels. (157)
Of course, worlds of difference separate Mark and the other gospels from the epics I think Horsley has in mind (Homer, Moslem Yugoslavian epics, etc.). But that's not the point Horsley's making. He's reminding us that Mark's story—impressive and complicated as it is—isn't really so impressive and complicated that it had to be composed by an author in possession of himself, deliberate and laboriously working at a table or desk, free of the distractions of the wide world around him.
Instead, Mark certainly could have been (I think probably would have been) the kind of story Jesus' followers told as they gathered together to learn, to worship, to fellowship, and to pray. Certainly at some point someone (let's call him Mark) wrote the story down—though strangely Horsley would disagree. But that doesn't mean that Mark's written gospel was the first time the story ("the whole [Gospel] story") was apprehended in a single social engagement by women and men devoted to Jesus. In fact, given that the first mention of Mark's gospel doesn't occur until early in the second century CE (Papias), I suspect no one thought what Mark had done to Jesus' story was particularly groundbreaking or innovative (pace Kelber). Mark's gospel provided another in a very large number of possible performances of the Jesus story, and before long Matthew and Luke (and even John) would show that Mark's story, indeed, wasn't even that long!