There's a distinction between songs that were customarily sung en masse at protest rallies, such as "We Shall Overcome," and topical songs generally presented in performance but not really suited for group singing, like "The Lonesome Death of Hattie Carroll." (Who would be expected to know all the words?)

The most popular of the picket-line sing-alongs have already been mentioned. But we've only scratched the surface in listing some of the many "topical" and "protest" songs that crowds would listen to without necessarily singing along.

Unless, of course, Pete Seeger were the performer, in which case he'd teach us all the chorus and make damn sure that everyone was participating before the song came to an end.