To save you the bother of following Derek's link, here's what I suggested a year and a half ago:

"It occurred to me recently, after reading Mike Bettison's piece in
English Dance and Song, in which he suggested that MacColl composed the well-known tune for 'Scarborough Fair', to compare that soaring Dorian melody with the one for 'Four Loom Weaver'. Try it yourselves, it's very instructive."

[It's also been suggested that EMC composed the tune to 'Four Loom Weaver']