I couldn't tell you exactly when it was but it should have been between 1989 and 1992. I was in high school then and remember everyone talking about it. I remember it starting some time on a Friday and continuing throughout the weekend till sometime Monday. Every once in a while the music would end, followed by silence for about ten seconds. Then the voice guy would come on and announce,"Just when you thought it was over..." Followed by "Rock & Roll" again. I don't remember what the stunt resulted in though.