### Jens Brand

####

**Sensoren und Streichhölzer /Sensors and Matches**

Performance for three participants, matches, computer and three ultrasonic sensors

Collaborative project with Waldo Riedl

1996

#### Three performers are seated next to each other at a table. A pile of matches is placed in front of each of them. Three ultrasonic sensors hang overhead which measure the distance from them to the tabletop. Each performer starts building a tower out of the matches, stopping when their tower collapses.

#### The sensors measure the growth of the three towers. The measurements are transformed by a computer into sound parameters. The middle tower determinates the volume. The volume increases in parallel with the construction of the tower. The tabletop corresponds to zero volume, i.e. the performance begins without sound. The other two towers determine the pitch of two sine waves. The tabletop corresponds to the same pitch for both waves. One pitch increases with the construction of the right tower and the other decreases with the erection of the left tower. A halftone step represents the greatest possible interval. The piece concludes with the collapse of the volume tower. /