At the most painful performance I can remember (in Boston, about 1960), the pain was no fault of the performer's. He was Josh White, and he was fine, but he had gotten saddled with an -- impresario? handler? what do you call him? (I know what *I* would call him, but never mind) -- who took up at least half the time opining about various things & telling insipid dirty jokes. He told a story about an early civil-rights demonstration that had the audience cheering the racists. Fortunately, there was enought light for me to read a magazine.