"The Light of Christmas Day," Robert Plant & Allison Krauss (Republic)

The unlikely duo who won a shelf full of Grammy awards together appeared to have left things lay for good with their Raising Sand album, until they popped up on the soundtrack to the 2015 Christmas-themed movie "Love the Coopers" with this holiday ballad, written by Charles Duncan of Ranchers For Peace. It's the same folky-country-ethereal sound Plant & Krauss perfected, so you should be able to tell if this is for you or if you're going to keep sitting shiva for another Led Zeppelin reunion.