While Paris students were rioting, American troops were razing My Lai and the Beatles were busy crafting odes to blackbirds, piggies and raccoons, Karlheinz Stockhausen was trying to recreate a recent vacation during which he walked among the ruins of ancient temples in Mexico. With Stimmung, a piece for six voices and six microphones, he very nearly did it. The great German composer here only affords the piece's six singers a few notes, all overtones of B-flat, and simply asks them to move slowly between them. The piece is in 51 sections, each with a distinct phonetic pattern. Twenty-nine of these patterns are built from "magic names," which come from the gods of a variety of cultures (Greek, Aztec, etc.). If you can ignore the hippie-dippie nature of the piece and simply focus on the content, though, you'll soon find it's pretty much ambient music before the genre was (re)invented by Brian Eno — endlessly fascinating under close scrutiny and just as pleasing when you're doing the dishes.