There is no evidence that these pagan English writers ever attempted to inscribe the songs and stories recited by the storytellers and bards of their time. Alliterative poems, and probably prose sagas, too; but such literature had nothing to do with litterae or written characters. The life-cycle of an English vernacular poem in the pre-literate fifth or sixth centuries would therefore have been quite different from what we are used to today. It would have been conceived and composed orally -- in the bard's head, that is, before and during the act of performance. That act of performance would also have constituted its only mode of publication. Indeed, the poem could only be said to exist at all so long as it, or a recognizable form of it, went on being sung or recited either by the original bard, or by members of his audience, or by their successors. When no one remembered it any longer, the poem died.
This must have been the life-cycle of many Anglo-Saxon poems but one can only speculate about their character, for there is no way of recovering an oral poem once it is forgotten. The Anglo-Saxon poetry which does survive (little more than 30,000 lines in all) does so because it was written down, not by the rune-masters, but by their successors, the Christian scribes.
J.A. Burrow, Medieval Writers and Their Work: Middle English Literature and its Background 1100-1500, 24.