Rafael Lozano-Hemmer’s technologically advanced installations are unusual in their ability to arouse curiosity and to quickly transport viewers into their field of engagement. For this exhibition—the U.S. debut of the piece Frequency and Volume, Relational Architecture 9 (2003)—the artist made it possible for visitors to physically interact with radio frequencies. This participatory work is a continuation of his “Relational Architecture” series, begun in 1997, which explores the relationships between architecture, cities, the body and technology, and expresses his desire to amplify human gestures to transform people’s experiences of public spaces.

Upon entering the first room of Frequency and Volume, viewers encountered radio equipment whose function was not initially clear. Once in the main gallery, they found their shadows cast onto a gallery wall by a row of projectors, and here the fun began. A computerized tracking system, designed by Lozano-Hemmer with a computer programmer, enabled the shadows to scan radio waves between 150 kHz and 1.5 GHz transmitted by the anteroom equipment and a sculptural antenna tower installed on an adjoining terrace.

As participants moved through the space, the volume and frequency of the radio waves changed in response to the size and position of the shadows. The aural experience was somewhat magical, as the collage of sounds ranged from AM talk shows and jazz radio to traffic control and satellite transmissions. The effect oddly evoked Christian Marclay’s Video Quartet (2002).

Lozano-Hemmer’s installation Homographies (2006) was concurrently on view at SFMOMA in the group exhibition “Field Conditions.” In a blindingly bright, stripped-down room with a charcoal-and-white-tiled floor (Tauba Auerbach’s contribution to the show), visitors quickly noticed that the 52 overhead fluorescent tubes changed angles in relation to their movements. This prompted the desire to test the responsiveness of the lights and created a play space of sorts. However, since Lozano-Hemmer again used a custom-designed tracking system to detect visitors’ presence and position, ominous overtones of surveillance also came to mind.

The motion sensors Lozano-Hemmer employs have an underlying political agenda. Born in Mexico City in 1967, the artist developed Frequency and Volume at a time when the Mexican government was shutting down pirate radio stations in indigenous communities in the states of Chiapas and Guerrero. This history raises questions about community, artistic censorship and access to information. By making us aware of the transmission of radio waves through direct engagement with our bodies, Lozano-Hemmer powerfully suggests that the politics of public communication are inherently personal.

Photo: View of Rafael Lozano-Hemmer’s installation Frequency and Volume, Relational Architecture 9, 2003, mixed mediums; at SFMOMA.