JennyO's post quotes some "Pagan Yule" carols, which are embarrassingly bad modern bowdlerised rewrites of traditional carols. There is quite a little industry of rewriting folksongs with the offensive bits removed(often references to drinking or Christmas, which tend to annoy certain people for various reasons). Fairly predictably, the results are not uniformly successful: the folk are rather good at writing folksongs, bowdlerisers aren't.