"The extract from 'Beowulf' above is just that. (Possibly why nobody sings it? :-)) "

Well, I'm afraid we're just going to have to disagree on this one, Paul. Beowulf was written (we assume) to be recited, possibly to harp accompaniment, in the rowdy atmosphere of mead halls where it had to cut through the din and catch people's attention - pretty much like many folk clubs :). I'm suggesting, as Peter Ackroyd does in the book I mentioned, that this form often comes unconsciously when writing ballad-style songs in English where Anglo-Saxon words are more appropriate that Latin ones. What's important is how the words sound (and even "feel" in the mouth) when they are sung. I certainly agree (as I pointed out above) that the choice of odd or different words is important and banality can be avoided by doing this. In the end, though, you write songs the way you want to and they are either good songs or not - whether they sound traditional is, to me, immaterial.