Philip Hensher: “It seems a tragic justification of the career of the author of Gruppen that it would lead, in the end, to a multi-million selling pop album called OK Computer. But such Lilliputian testaments were very much in the air in 2007 because, for the best part of 30 years, the people who understood what had made Stockhausen interesting in the first place were generally not willing to stand up for his whole career. Since the mid-1970s, the composer who had once ruled a vast swath of contemporary taste had turned into a curiosity.”