It would be easy to assume the two figures hanging out in a vacant North Avenue lot on a recent rainy evening are up to something nefarious–possibly illegal. He’s holding a plastic stencil in one hand and a can of silver spray paint in the other, while she consults from a few feet away.

Aay Preston-Myint, a student and tour guide at the Art Institute, and Ilana Percher, an applications engineer, are the founders of the Chicago Tapes Project, a participatory art endeavor launched in April as part of Version>05. Part secret Santa, part public-space reclamation, the project has so far planted at least 30 anonymous mix tapes around the city.

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The tape, says Preston-Myint, was found under the Bloomingdale viaduct at Western, in a hole in one of the supports, about a foot off the ground. “I haven’t listened to the whole thing,” he says, “but it’s kind of experimental, a guy talking or reading over sounds. Or maybe people having a meeting. I’m not sure.”