Ryoji Ikeda is a Japanese sound artist who lives and works in New York City. Sometimes harsh, sometimes remarkably gentle, Ikeda's music is concerned primarily with sound in a variety of "raw" states, such as sine tones and noise, often using frequencies at the edges of the range of human hearing. The conclusion of his album +/- features just such a tone. Rhythmically, Ikeda's music is highly imaginative, exploiting beat patterns and, at times, using a variety of discrete tones and noise to create the semblance of a drum machine. His work also encroaches on the world of ambient music; many tracks on his albums are concerned with slowly evolving soundscapes, with little or no sense of pulse. In addition to working as a solo artist, he has also collaborated with, among others, Carsten Nicolai and the art collective Dumb Type. His work matrix won the Golden Nica Award in 2001.