Parade and Bricklaying were written in March 1990 to document and demonstrate some of the self-playing machines I built for various performances and installations over the past five years. Microphone placement for recording has significantly altered the audio characteristics of some of the machines from their original usage. All seven machines use metal as their main sound sources. They are all electrically powered, and work like this:
1. Four table tennis balls roll on a rotating metal hot water service lid. A contact miked bamboo pole positioned like a billiard cue just inside the lid's rim knocks the balls apart when they congregate there.
2. Two wooden beads suspended from a rotating T-arm structure strike 25 tin cans placed in their path. The cans are of different sizes and open or closed. They rest on their sides or ends to maximise pitch and timbral variety.