Pink Floyd's sound and light shows in the 1960s defined psychedelia, but their later recordings combined rock, orchestral music, literature, and philosophy. ''Dark Side of the Moon'' and ''The Wall'' ignored pop music's usual strictures to focus on themes of madness, despair, brutality, and alienation. Here, 16 scholars set delve into the heart of Pink Floyd by examining ideas, concepts, and problems usually encountered not in a rock band's lyrics but in the pages of Heidegger, Foucault, and Sartre. These include the meaning of existence, the individual's place in society, the contradictions of art and commerce, and the blurry line between genius and madness. The band's dynamic history allows the writers to explore controversies about intellectual property, the nature of authorship, and whether wholes, especially in the case of rock bands, are more than the sum of their parts.