Pink Floyd is the premier space rock band. Since the mid-'60s, their music relentlessly tinkered with electronics and all manner of special effects to push pop formats to their outer limits. At the same time they wrestled with lyrical themes and concepts of such massive scale that their music has taken on almost classical, operatic quality, in both sound and words. Despite their astral image, the group was brought down to earth in the 1980s by decidedly mundane power struggles over leadership and, ultimately, ownership of the band's very name.