De Balie in Amsterdam was officially opened on 15 January 1987. The invitation to provide audiovisual backup for the opening resulted in the film project ‘National Signals’. Details of majorettes and a drum band were projected with twelve film projectors and twelve film loops from the offices that surrounded the room for festivities. The images were projected onto white screens surrounded by draperies that had been set up in place of doors. The majorettes and the musicians moved from one doorway to the next and vice versa. The images were accompanied by the loud sounds of the composition National Signals.