> Does "noir" in this context indicate race, the > "choleric humour," or perhaps, the long black > gowns of clergy, as in "Blackrobe"? Or is there an > alternate possibility?

It's morally black, evil.

> L'histoire et le provenance > de votre chanson, s'il vous plait?

I don't know where it comes from. It's not literary French - it could come from Quebec or from a rural part of France (eg Britanny). And it's old but not very old (18th century?). Never heard the story before.