When Ryoji Ikeda's groundbreaking album +/- was released in 1996, there were very few precedents for its sparse, clean, rhythmic electronics. Composed of two suites, "Headphonics" and the title work, +/- defined the microwave or glitch genre that became relatively popular in the late 1990s. "Headphonics" starts with sine tones alternating in each channel at the same pitch, then layers different elements in each of the three sections of the piece. Each layer is clearly distinguishable, whether it is the high pitched trills, low bass tones, or the rhythmic click track. The work builds to a climax in 1/0 with arpeggiated bass rumbles and increasing volume in the background drone. The title work is really in two parts marked by the initial character in the track title. The pieces starting with "+" are based on a helicopter-like rhythm track where the overtones subtly change pitch. With the exception of a little bit of reverberation at the end of "+..," the dry rhythm track is the only element in these three pieces. By contrast, the tracks beginning with "-" are drone pieces, where the drones are layered and accompanied by sonar-like pings. In the closing moments of this second set of three pieces, the drone suddenly stops, leaving a quickening series of high-pitched tones which become quite loud. The last track is short and composed only of supersonic pitches and will be all but inaudible for most listeners. The album has none of the noisy work typical of Ikeda's later releases, but has a sparse and simplistic beauty that remains unsurpassed.
AllMusic Review by Caleb Deupree