The holiday season is not without its distasteful aspects—family obligations, crass commercialism, fruitcake—but, with the exception of the kind piped into malls, Christmas music isn’t one of them. Besides, there must be some reason why more people know all 12 verses of “The Twelve Days of Christmas” than know the words to the National Anthem. There’ll be ample opportunity to sing along at the Oratorio Society of Washington’s annual “Music for Christmas” concert. The Society is joined by the National Symphony Orchestra’s brass and woodwind sections, NSO organist William Neil, and the Woodson High School choir for performances at 5 p.m. today and 8:30 p.m. Thursday at the Kennedy Center Concert Hall. $9-30. (202) 342-6221. (Nicole Arthur)