One technology of surveillance of electronic devices is the inductive recording of electromagnetic fields. The extent of such intrusions was documented in the Snowden leaks and again in the “CIA Hacking Tools” released by Wikileaks in March 2017. These invisible techniques of accessing private data can be experienced in the installation Surveillance Music as sound. The installation consists of four parts: Polygon, hard drive, pedestal and inductional coil microphones. The white smooth polygon is floating two meters above ground, attached to three thin metal strings. It features speakers on the sides and black cables hanging down from three openings. Connected to the end of the cables are inductional coil microphones. These move vertically in the electromagnetic field of the hard drive, controlled by a computer and motors hidden in the polygon. The microphones transform the electromagnetic field into our range of perception and makes it audible through the speakers. In the process of making the electromagnetic field of the hard drive audible, the data on it is part of the sonic fingerprint and of the composition. The programmed movements of the inductional coil microphones form the music. The installation is looped.