John Forster's song "Fusion" was mentioned in this thread where there is a link to the words. I wouldn't say it was about Simon's so-called "thievery" so much as about his ego.

Speaking of old German melodies, there's also Pete Seeger's "Of Time and Rivers Flowing", which he sings to Es ist ein' Ros entsprungen, first published in 1599 so far as I know.

An example of a song that was unsuitably arranged as a pop song is Gordon Lightfoot's "Wreck of the Edmund Fitzgerald". His arrangement, heavy with loud percussion and electric strings, seems inappropriate to the melody and words. Softer instruments and lighter percussion (or no percussion) would probably have suited the song better than Lightfoot's particular arrangement. If only the term of copyright were shorter (I can't resist bringing up this point) we might hope to live to see myriad public experiments at arranging this song, from jazz versions to disco to classical to oom-pah oom-pah, and we'd get our pick of whichever we liked best. But as things stand, I doubt such riotous freedom will ever be allowed for this song in our lifetime. The compulsory license mechanism for sound recordings forbids a performer "covering" a song from changing the "basic melody and fundamental character" of a work, 17 U.S.C. 115 (a) (2).

T.