The song in the Herd MS. says only that if the damned bird would keep quiet until day, the girl tells him its wings could be like beaten gold and its wings silver grey. But a cock crows when it feels like it, and crows early.

A very simple song, no ghosts, no suggestion of old votive practices.

When did the version with the lover returning as a ghost appear? From Steve Gardham's posts, it seems to be about mid-19th C.