The post you are reporting:
A Penguin Classic, 'Medieval English Verse', has this foreword to the tale:Sir Orfeo...
"'Sir Orfeo', on the poet's admission, is a 'Breton lay'. The word 'lay' means, in English as in French, a song or lyric: it was after the time of Marie de France, who professed to derive her poems from Breton sources (originality was not respectable in the Middle Ages: one was expected to have a reputable source for any creative work), that the term 'Breton lay' came to mean a short romantic narrative in verse, either for reading or for chanting to some kind of musical accompaniment. However, no lays in the Breton language have survived, if indeed there ever were any. All that can be said about the very few in English is that they seem to have a strongly Celtic atmosphere, even when their immediate sources are French. According to Sisam, "Sir Orfeo" appears to have been translated from a French source into south-western English at the beginning of the fourteenth century. The lofty romantic spirit of the poem may be compared with that of Chaucer's Franklin's Tale, which the Franklin defines as a Breton lay. Although the Franklin's Tale came ultimately from ancient Sanskrit, and 'Sir Orfeo' from Ovid's version of the Greek myths*, both stories, as we have them, are thoroughly medieval in spirit."
*
Orpheus and Euridice
P.S.
Mallory's tale is rich in detail though. As I recall every piece of Falconry's kit is minutely described.
