Sonic Vista, by O+A, Bruce Odland and Sam Auinger, is a permanent sound installation commissioned for the 20th anniversary of the Frankfurt Greenbelt. It offers visitors the perfect site to hear the whole city. A gentle halo of harmonically tuned real-time sound emanates from two “Sphere” loudspeakers which radiate the sound in all directions without “hot spots” and function as a visual attraction seen from the whole city. This listening spot now connects the north and south portions of Frankfurt’s famous Greenbelt.