by Jason AnkenyFormed in 1970, Guru Guru was a German prog rock outfit whose largely instrumental work set the group squarely within the boundaries of what is commonly referred to decades later as Krautrock. While guitarist Ax Genrich, Uli Trepte, and keyboardist/drummer (and Cluster collaborator) Mani Neumeier remained the core of the band throughout its ten-year existence, a number of other musicians passed through the bands ranks, including Cluster co-founder Hans-Joachim Roedelius, who played keyboards on 1976s Mani und Seine Freunde, and keyboardist Ingo Bischof, who assumed increasing control of the group until its 1979 dissolution following the release of Hey Du, recorded under the name the Guru Guru Sun Band.\r