The Christmas season may be a boom time for retailers and a joyous occasion for families, but it’s become a giant headache for public schools. Vague court decisions and virulent disagreement over the extent to which religion must be kept out of schools have resulted in a patchwork of rules governing what is and is not allowed in a school’s “holiday” concert and celebratory display. “Schools often fall into two camps: They quietly avoid religious songs in favor of more generic tunes such as Frosty the Snowman and Jingle Bells. Or they offer a sprinkling of songs from different religions and fill much of the concert with secular holiday songs.”