The sumptuous, post-Edwardian world of Downton Abbey is well suited to Yuletide celebration. Christmas specials of the popular award-winning TV series are already an annual tradition, which makes this double album the perfect stocking stuffer for fans of the aristocratic Crawley family and their servants. Many of the 45 tracks are sung by the likes of Dame Kiri Te Kanawa and the Choir of Kings College. And the Budapest City Orchestra performs an extended festive-suite version of the series theme. But the songs that will most excite Downton followers are those sung by cast members. Elizabeth McGovern (Lady Cora) delivers a jaunty “It Came Upon a Midnight Clear.” The American actress, who fronts the folk-country group Sadie and the Hotheads, also joins Julian Ovenden (Charles Blake) on a stately duet of “The First Noel.” And who better to recite the classic “’Twas the Night Before Christmas” than Jim Carter, who plays Carson the bashful butler?