There are at least 5 bands named Cluster (a German ambient musical group, a French "heavy rock" band, a Brazilian band, an Italian vocal group, and a bolivian "punk rock" band) 1/ Cluster is a German musical group closely associated with krautrock whose output prefigures ambient music. Michael Waynick, who reviewed Cluster & Eno for Allmusic writes a description that applies to more than the one album: "...too emotionally rich to waste as mere background music