Cluster were a German musical group formed by the duo of Hans-Joachim Roedelius and Dieter Moebius in 1971 and associated with West Germany's krautrock and kosmische music scenes. Borne from the earlier Berlin-based group Kluster, they collaborated with musicians such as Conny Plank, Brian Eno, and Michael Rother; with the latter, they formed the influential side-project Harmonia. After first disbanding in 1981, Cluster reunited several times: from 1989 to 1997, and from 2007 to 2010.