Y'all seem to be seriously offbase here. Nothing about Christmas can be, by definition, secular. If you want ACTUALLY secular songs that are performed in midwinter, which it sounds as if you do, try Winter Wonderland. I don't know all the words to Chestnuts Roasting, that might pass muster also. Anything with Santa Claus in it is about Christmas which is religious, and in particular Christian, whether you want it to be or not. Aren't there any good SOLSTICE songs? Now that would be secular. The earth revolves in reality, not in religion.