Founded in 1967 by Edgar Froese in Berlin, Tangerine Dream has progressed through a full three dozen lineups (Froese being the only continuous member with staying power) and four distinct stages of development: the experimentalist minimalism of the late '60s and early '70s; stark sequencer trance during the mid- to late '70s, the group's most influential period; an organic form of instrumental music on their frequent film and studio work during the 1980s; and, finally...