Founded in 1969, German ambient space-rock pioneers Kluster were originally a trio featuring Conrad Schnitzler, Hans-Joachim Roedelius, and Dieter Moebius. During their brief lifespan (before Schnitzler left in 1971 and the duo renamed themselves Cluster) they recorded three LPs, all of which are available here. The first two records, Klopfzeichen and Zwei-Osterei, recorded in 1969 and 1970 respectively, were sponsored and released by a church-run record label (Schwann) and as a result of contractual obligation, featured religious-themed text on the first side of each. The trio's third album Eruption was a live recording of the band's last concert together in 1971. All three are amazing examples of pioneering ambient music featuring guitar, percussion, keys, and cello heavily processed with echo, filters, and tape machines to create an effect unlike anything else that was being made at the time. Absolutely essential and seminal progressive music. Contains liner notes.