Though Steve Reich's trailblazing minimalist compositions have had a huge impact on everything from rock to electronica, Reich didn't really reach an audience beyond the avant-garde cognoscenti until the '70s. The pieces collected here from his early career—mostly from the '60s—eventually became influential, but they remained a kind of buried treasure for years. As with most great minimalism, the simplicity of these compositions is simultaneously disarming and devastating. "Come Out" manipulates a tape of the voice of a young man caught up in the Harlem Riot of 1964, looping a single phrase into aural abstraction. "It's Gonna Rain" achieves a similar effect, with the voice of a Pentecostal preacher delivering an apocalyptic sermon. "Piano Phase" takes a more conventionally "musical" performance approach to the same idea; two pianists start playing in unison but gradually grow further and further apart to create a dazzling tapestry of ostinato lines. "Clapping" is ostensibly the simplest of all, applying the basic concept behind "Piano Phase" to two pairs of human hands coming together and drifting apart.