What cassette recording are you talking about?Arlo Guthrie, appropriately, does a wonderful job on this song on the Folkways release "A Vision Shared" tribute to Woody & Leadbelly album.
I don't know about Sir Gawain, but I was struck by the classical structure of the plot--the song has bones AND beef. Or as you might way, its got parts.
Thanks for the lyrics Art.
Bill