What have they done to my song? The medieval Ashkenazi maestro who penned the poem we now call Maoz Tsur (in English, “Rock of Ages”) might well have asked this question. True, Mordechai—his name is encoded in the first five stanzas—is a mysterious figure; one can only surmise that he lived in Central Europe near the end of the 12th century. But the lyrics of his celebrated song should leave us in no doubt: were he transported to a modern-day menorah lighting, he would be dumbfounded to hear that we have made Maoz Tsur into a song for Hanukkah—and, to boot, one commonly sung to a German melody more suggestive of Rhenish good cheer than of his simultaneously witty and very serious sweep through Jewish history and destiny.