One of the most popular and challenging albums in rock's history

As much an aural collage as a straightforward art-rock treatise, the album uses its 43 minutes to link speaking voices, sound effects-heavy musique concrète, a bravura performance by session singer Clare Torry (“The Great Gig in the Sky”), moody existentialist statements (“Time,” “Us and Them”), and a funk-rooted strut (“Money”).