Free Bird
At the Ben Gibbard show the other night, Caroline wondered aloud about the origin of yelling "Free Bird" at shows. I said Wikipedia must have the answer, and it does. Strangely, or perhaps not, its origin has to do with Skynyrd not playing the song during an encore at a 1976 show. Crowd chants can be heard on the live album One More From The Road before the band returned for its second encore, when it of course played "Free Bird." So there ya go. (Update: more in this WSJ article, including the Bill Hicks stuff that Mat mentions in the comments.)