30 odd years ago, I saw Fairports at The Rainbow ( what's it called now, btw) in London. At the end of the evening they finished with a rock'n'roll medley. This received the best response of any piece from the whole performance. Such audience reactions bother me. Time and time again, I've seen an artist giving a wonderful performance of what they are renowned for, but they get the biggest cheer for the " novelty" number at the end.