I found part of this clip elsewhere, but missing Cash's extended spoken introduction. I hate to sound like a college nerd (because I'm not, I just married one), but the additional context his remarks add make the song even more impressive to me. This was from the February 17, 1971 episode of his show, by which time the Suits had forced him to start doing "theme" shows. This is from the best of the bunch, "Johnny Cash On Campus," which also featured Neil Young and James Taylor. It's super cool to hear Cash introduce what would go on to become his signature song to zero crowd applause. It's like hearing a recording of Zepplin play "Stairway..." to audience indifference before the album was released. Shiver me timbers!