A powerful electric fan—an integral part of the artist Kris Marten's half-inflated hot air balloon, T.Y.F.F.S.H. (2011)—will be blowing in the Museum of Contemporary Art (MCA) Chicago, from 9 May to 4 October, as a part of the exhibition S, M, L, XL, which will have four pieces by four artists of different scales. “We thought about calling the show Body Mass Index,” says the co-organiser Michael Darling, but with another recent show that had the word “body” in the title (Body Doubles, until 19 April), the curators reconsidered. Often used to label clothes, the abbreviations gained intellectual kudos in 1995 when the architect Rem Koolhaas and the designer Bruce Mau used them as the title of their book that riffed on urbanism. With four works on show, it made a good fit, Darling says.