At the beginning of their set covering all of Master of Puppets, JL lost his place with the lyrics to Battery because he was relying on a teleprompter for the lyrics, and the teleprompter guy had screwed up and wasn't cycling thru the lyrics like he was supposed to. IIRC, the problem didn't get sorted out until the end of the song, so we got an instrumental version of that song. But on the up side, JL was so pissed off as a result that he gave a fiery performance for the rest of that set, which benefited those songs.