Cluster is a German musical group whose output prefigures ambient music.
Having previously collaborated in the use of electronic instruments and experimental technique, Dieter Moebius, Hans-Joachim Roedelius, and
Conrad Schnitzler formed Kluster in 1970. This trio released three albums, Klopfzeichen, Zwei Osterei, and Eruption. When Schnitzler left the
group, Roedelius and Moebius became Cluster, and worked extensively with producer/engineer Conny Plank until his death in 1987.