Cornelius Cardew, who had been Stockhausen's assistant and had played celesta in the world premiere. In 1972 Hans Keller asked him to introduce a broadcast of the work on BBC Radio and Cardew, a recent convert to Marxism, seized on its comparative popularity as an opportunity to condemn the composition as "a part of the cultural superstructure of the largest-scale system of human oppression and exploitation the world has ever known: imperialism". Writing in what has been described as "the most vulgar style of Marxist conventions", Cardew viewed the European avant garde, whose "abstruse, pseudo-scientific tendencies were encouraged in ivory tower conditions" as having been by 1959 "ready to crack from its own internal contradictions". The leading figures of this group, at the head of which stood Stockhausen, were eager to find a broader audience, and achieving this required change. "Refrain was probably the first manifestation of this change in Stockhausen’s work. Since then his work has become quite clearly mystical in character". Because "Mysticism says 'everything that lives is holy', so don’t walk on the grass and above all don't harm a hair on the head of an imperialist", Refrain "is an ally of imperialism and an enemy of the working and oppressed people of the world", and is comparable with other manifestations of imperialism, specifically "the British Army in Ireland and the mass of unemployed, for example. Here the brutal character of imperialism is evident. Any beauty that may be detected in Refrain is merely cosmetic, not even skin-deep". Publication of the first half of Cardew's lecture in The Listener "provoked a storm in its correspondence columns". and, as a result of this and a similar attack on John Cage, Cardew reported that "I temporarily lost my voice at the BBC". According to his testimony, "Punishments were also meted out inside the BBC on account of the Stockhausen broadcast which by mischance was heard by a high official of the Corporation". Discography Karlheinz Stockhausen. Zyklus, Refrain. Mauricio Kagel, Transición II. Christoph Caskel (percussion); Aloys Kontarsky (piano); Bernhard Kontarsky (celesta); David Tudor (piano). With LP recording, stereo. Series 2000. Time S 8001. [N.p.]: Time Records, 1961. Reissued, 1970s, LP recording, stereo. Mainstream MS 5003. [N.p.]: Mainstream Records. Reissued on CD as Karlheinz Stockhausen, Mauricio Kagel, Earle Brown; Udo Wüstendörfer; Karlheinz Stockhausen; Mauricio Kagel; Christoph Caskel; Aloys Kontarsky; Bernhard Kontarsky; David Tudor. Mainz: Schott Wergo Music Media, Wergo WER 6929