Variations on a Topography is constructed in stratified layers, each containing a recording of a full scan of the AM/FM spectrum from bottom to top and back down again. Tuning through the spectrum in the same place every time, Kohl charts a map of her specific signal, showcasing the geographic specificity of radio and drawing out its topography with additional musical sounds. Cello and synthesizer highlight moments of clarity and static, creating a counterpoint ruled by the dichotomy between them. These “signal sweeps” also offer a sedimentary view of time, capturing multiple 28 minute sections of what would otherwise be completely ephemeral sounds. The recordings, taken over the span of a few months, speak in various ways to the passage of time – the weather gets colder, traffic patterns shift, wars break out. The signal, like a ghostly mountain range, hovers around us.