1975’s Discreet Music forms a bridge between the peaceful instrumental passages that Brian Eno featured on Another Green World and the full-blown “ambient music” that he'd introduce on a series of albums in the following years. The 30-minute title song isn't so much performed as manifested. Two synthesizer phrases of differing lengths are repeated and treated, overlapping with each other in subtly unpredictable ways. The result is music that's more about mood, texture, and tone than melody, rhythm, and lyric. The album's second half employs a similar tactic with a different outcome. Eno gave a small string ensemble (conducted by Gavin Bryars) brief excerpts of a piece by 17th-century composer Johann Pachelbel; the musicians were instructed to repeat the passages several times, gradually adding adjustments in tempo and timbre. Though Discreet Music borrows heavily from the practices of such revered avant-garde musicians as John Cage, Terry Riley, and Steve Reich, Eno’s music is neither cold nor cerebral. This conceptual music resounds with rare emotion and warm majesty.