A car with a modified mobile home trailer stood on Rossmarkt, a large central plaza in Frankfurt, for six months. The duo changed location on the plaza at irregular intervals during this time, thus continually mapping the space in new ways. Four white wooden horns have been built into the window cases of the trailer. A permanent ticking sound can be heard. There are altogether 18 different indicating sounds announcing the passing of second after second: These sounds change at random every 15 minutes. The sounds move across the plaza in different ways, depending on how the car is placed in relation to the surrounding architecture and can be heard from different perspectives. At each full hour between 8 a.m. and 8 p.m. the ticking is interrupted by musical compositions. Five musicians and composers living in Frankfurt were invited to develop 13 short pieces. Most of the invitees work in the field of music and work with sounds in unusual ways. The trailer features a window with a listing of the times, composers, lengths of the pieces etc. The musical compositions are exchanged at irregular intervals. In the evenings the trailer is lit up from the inside.

Since its first showing, the car and trailer have made appearances in different cities, with local musicians or composers invited anew in each city to create new hourly sounds to be played.