This CD presents two live performance interactive compositions involving the amplification of brainwaves or the human nervous system to control electronic sound modules of various sorts. The first piece entitled "Portable Gold and Philosopher's Stones (Music from Brains in Fours)" (1972) has as its central image the investigation of the "prima materia", or that original, constantly mutating, undifferentiated substance of the universe that can be reached through sensation and highly differentiated thought. The brainwaves of four performers are monitored as they set up ringings along the sub-harmonic natural series in a series of high-Q or resonant filters. The mixture of these gently sweeping, sometimes trilling, sounds is meditative and healing. "On Being Invisible, Parts I and II" (1976-77) is organized in a feedback system which analyzes changes in the structure of the performer's responses and makes corresponding changes in the system itself, thus becoming self-organizing or heuristic (self-teaching). The brainwave-controlled sounds in this piece are more playful, often droll, stable and de-stabilised. In Part II, the input sounds and analyses are derived from acoustic sources rather than brainwaves performer may make sounds at his/her own discretion into a microphone which changes the system.
AllMusic Review by "Blue" Gene Tyranny