"Caedmon's Hymn" I suppose must be called a religious work although it was not part of liturgical chant. Some question the validity of Bede's story, but, written by Caedmon or some anon. monk, it certainly is one of the earliest English poems.

I think the attempt to identify early song as 'folk' is wrong. Wouldn't it be better just to say 'English song' and not engage in rather fruitless speculation as to 'folk' origin?