Matrix

Japanese composer Ryoji Ikeda continues to test listeners’ hearing on his fourth full-length. Matrix is a two-disc set. The first disc, “Matrix [For Rooms]” consists of an hour of pulsating, tinnitus- and sinus-activating pitches that get almost impercetibly faster and slower, sometimes blending together until they become a continuous hum, and seem as if by magic to shift depending on where you are in the room. (On headphones, the effect is diminished, which makes it all the more magical.) The second disc, “Matrix [99-00]” is only half as long (30 minutes to the first disc’s 60) and adds tiny static crackles and low, heartbeat-like pulses to the test tones. This music has an austere beauty, but it also has physiological effects; when you take the headphones off, you’ll be more aware than ever of your refrigerator, your radiator, and all the other small, steady sounds you’ve been tuning out for years.