Imagine finding a message in a bottle, forty years after it was dispatched. That is what it feels like when you listen to Kluster's Klopfzeichen for the first time, mysterious, hard to decipher, a relic of a time long since passed. The handwriting is archaic, barely legible, the complex contents only falling into place when examined through the light of historical context. Klopfzeichen is an incredibly important release for the time in which it appeared (1971), an extraordinarily significant document. More than anything, the three messengers Konrad Schnitzler, Hans-Joachim Roedelius and Dieter Moebius formulated a radical claim with Klopfzeichen: anarchic, unlimited freedom of art and music. Kluster's music may have aged, but their message has not. That the recording session happened at all is, curiously enough, due to a church musician, a man one would then have described as extremely progressive. Oskar Gottlieb Blarr not only made it possible for these musical enfants terribles to work in Düsseldorf's Rhenus Studio, he also orchestrated the release of Klopfzeichen shortly afterwards through the Schwann Verlag, a publisher closely associated with the church, on their own record label, AMS Studio (subtitled "Werkraum für neue Kirchenmusik"/trans. "workspace for new church music"). This "ecclesiastical" affinity is probably the reason for the strongly-committed political and religious texts spoken over the music on the A-side. Kluster lyrics they are not, and they sound a little strange today. True to their understanding of artistic freedom (Joseph Beuys was undoubtedly an influence), Kluster improvised with all sources of sound they could lay their hands on: guitar, bass, cello, flute, drums and various other pieces of equipment not usually intended for musical use. None of them could profess to be an expert on any of the instruments. They were brilliant dilettantes, a decade before the concept was invented. Electronics? No sign of them. The budget did not stretch to synthesizers or anything of that ilk. That said, a certain Conny Plank was on board as sound engineer for the early recordings. He added an apocalyptic character to Kluster's menacing and chaotic music. Klopfzeichen was the most radical album of the early German pop music avant-garde by a country mile. Its sounds and noises had nothing in common with the sequencer-generated electronic music emerging from Berlin or Düsseldorf. Kluster music was Angstmusik, the music of fear. Liner notes by Asmus Tietchens.