All sounds are produced acoustically (without loudspeakers), but are controlled by computer. The sounds are created by mounting variable speed (24 V DC) motors onto steel sheets of various sizes; the motors have off-centre weights attached to the shafts so that when the motors turn, a physical modulation is transferred to the metal sheeds. The motor speeds are varied so that an extreme spatial effect takes place, where the sound travels around the room as each of the six motors changes speed (causing timbral and dynamic changes) in relation to each other. The piece is controlled using MAX music software to precisely control the speeds of the motors. Each motor is assigned to a MIDI note name, and velocity numbers from o to 127 correspond to voltage values from 0 to 24 volts DC.
The velocity numbers can be preprogrammed or run in real time using mouse control. In the case of this recording, the velocity numbers were pre-programmed and read from a value table.
There are two large stainless steel sheets (3 meters x 1.2 meters x 1 mm.) that are hung vertically, the motors being mounted on the top of the sheet. There are 4 smaller sheets ranging from approximately 60 cm x 80 cm. to one square meter. Each of these four sheets has a motor mounted in the centre, and the sheets are hung horizontal to the ground.

Gordon Monahan (CDN), born 1956, Kingston, Ontario. Gordon Monahan's works for piano, loudspeakers, video, and kinetic sculpture span various genres from avant-garde concert music to multi-media installation and sound art. He is also artistic director of the KBZ 200, a group specializing in 14-hour "Vexations" performances of music from the 1950's Exotica movement.