At the base of a stairway cut from a stone wall in the village of Cully, Switzerland, is a glass enclosure resembling a large mid-century pill, balanced on a thin steel plinth. Inside, at the time of writing, is a diptych of symmetrical ears in acrylic under glass. In the right ear (our left) is a butterfly at rest beside the canal's entrance, with wings like inverted auricles. Third Ear by Sarah Margnetti is 16 x 24 cm, but because of its miniature setting in the Kunsthalle Marcel Duchamp (KMD) at The Forestay Museum of Art, it imposes itself on any passerby who stoops to view it.

KMD was founded by Swiss artists Caroline Bachmann and Stefan Banz in 2009, to commemorate a conference of Duchamp research. The Forestay river bears special significance, as its waterfall is the setting of the Dadaist Duchamp’s last work, Étant donnés: 1° la chute d'eau, 2° le gaz d'éclairage. Created secretly over 20 years during his supposed retirement, and only mounted after his death, the installation (housed in the Philadelphia Museum of Art) is composed of a large wooden door set within a brick facade. Through two peepholes, the viewer can see an assemblage of found, painted, photographed, and mechanical...