Kommen und Gehen was commissioned by the German pavillion at the World Expo in Hannover last year. It is conceived for violin and tape/live electronics. As the audience is fluctuating permanently through the building, the actual piece was prepared by a “preface” and a sound installation in the hall, which serves two purposes. While permitting people to stay or to leave the building at will, it tries to gain the attention of the audience using a strictly processural setup: The preface consists of a single pitch, played by the violin. This note is recorded and transmitted—electronically transformed—through the loudspeakers. In principle, the installation is a kind of “digestive” process, in which the resulting sounds are repeatedly transmitted through the system, and once again transformed. This recursive process, which is closely related to structures I often use in my compositional work, leads to a densification of sound. In the original version, this process takes about two hours and has been shortened on the CD.

The final piece for Violin and Tape starts with the densified sound, which is abruptely stopped by a Bartok pizzicato on the violin. Like the installation, the piece also transforms sounds originally performed by the violin and refeeds them into the system, thus creating a network of the live violin and the sounds it originated. Since the algorithms used for both the installation and the concert piece model some sort of artificial life, the basic idea is quite simple: the violin is confronted with the “creatures” it created.

All the parts of the tape and the violin have been generated with programs I developed especially for that piece. The transformations mainly use a kind of recursive granular method, which is linked in many ways to contemporary models of communication and perception.