There is a clear spatial hierarchy at art fairs: modern and old master works on one side, contemporary on another. But this year’s SP-Arte, in its 11th iteration, inaugurated a new section called “Open Plan,” installing the most ambitious and large-scale works on the third floor of Oscar Niemeyer’s Bienal pavilion, a space usually left empty. High above, hanging over the curvy ramps of the modernist building, is a makeshift bridge, a fragile structure of wood and strings built by artist Rochelle Costi (Residência – escada, 2010/15, presented by Luciana Brito, São Paulo; Celma Albuquerque, Belo Horizonte; and Anita Schwartz, Rio de Janeiro), that casts a shadow over the main exhibition hall below. The dangling footpath that sways and rocks to the buzzing crowd all around stands as an informal line of demarcation, dividing the pristine upper floor, where works stand free of constraints, and the packed fury of sales at booths and stands throughout the rest of the pavilion. In all its uselessness, it’s a symbol of fairs’ deepening crises of identity as they increasingly want to resemble institutional exhibitions. When it comes to this particular building in Ibirapuera Park, the crisis is even more resonant. Home to both the …