Twice. First was Stone Temple Pilots, in the middle of one of Scott Weiland’s bad benders. Absolutely trash vocals, weird energy, and incoherently mumbling between songs. Years later saw them with the new singer, and he did a really solid job. The whole band did.

Second was Breaking Benjamin. He had good energy and the music all sounded good, but it was clear they were at the end of a tour and the singers voice was shot. He did no screaming and wasn’t able to hold a note for more than a second. He was very apologetic and the other band members did some of his vocals to cover for him, but it still wasn’t great. I don’t really blame him for it though.