How often are you likely to listen to a 100-minute composition of strongly rhythmic character for string quartet? If the answer is, often enough to buy a recording, you'll want this one. Terry Riley was a proto-minimalist who remained on the fringe of public awareness while others such as Glass and Reich became popular. This piece doesn't sound like anyone else's work, but it's likelier to appeal to people who like Glass and Reich than to those whose taste stops at Beethoven. Riley writes fascinatingly for string quartet, and of course he gets a performance of boundless energy from Kronos.