Sociacoustics ---
The Wriezeren Freiraum is a free space, one activity that the
Berliners associate with freedom is grilling. Only a limited number
of parks in the city allows people to enjoy this freedom; Since
the Wriezener Freiraum should be one of them, a special type of
stone tone-grills is developed for this place. When the coals
burn, hot air is lead through a revolver-construction of low whistles;
this allows the griller to choose the tone. When several grills
are used at the same time, a harmony of whistling grills can be
heard, luring the people from the neighbourhood into the park.