Almost every revolutionary movement in modern history—the labor movement, the civil rights movement, the anti-apartheid movement, and so many more—has had an accompanying singing culture. In the early 20th century, the Industrial Workers of the World, a radical labor union, had its labor demonstrations interrupted by the Salvation Army band. We sing songs like “The Red Flag” (sung to the tune of “O Christmas Tree,”) or make up our own parodies. As in a karaoke room, caroling brings a private event (a Christmas party) into a public space: It creates an opening. Sing in Solidarity goes caroling in support of candidates running for local elected office in New York City.