The Night Sounds (Shawn Decker, 1998) consists of four corrugated buckets, each approximately half-full of water which are each hung from the ceiling, suspended by piano wire. The buckets are each placed in the corner of a 10' by 10' square.
Attached to the tops of the piano wire (the tension of which is supplied by the weight of the bucket, and is regulated by the amount of water) are small motors, with a thin cord which strikes the string once for every revolution of the motor's shaft.
A micro-controller, with a custom program then controls the acceleration/deceleration and overall speed of each motor independently.
The speed of the motors varies widely, from only a few revolutions per second (simple ticks) to several thousand revolutions per second (in the audio range, causing complex interference patterns between the speed of the motor and the resonant frequency of the piano wire). The buckets themselves serve to amplify and radiate the sounds.
The patterns of the piece are modeled after crickets and cicadas found in the midwestern US. Having grown up in Western Pennsylvania, and lived in the mid-west, these sounds are ever-present in the summer.