From Central Park to Little Island and Battery Park City to Lincoln Center, New York public spaces abound in outdoor dance during the summer—and most of it is free. But what you save in ticket price, you often lose in rigor and novelty: the offerings tend toward old chestnuts and audience-pleasers. The big exception is River to River. This two-week free festival not only takes place downtown, it is “downtown,” as we used to say to indicate the local avant-garde. It does not ingratiate. This year the emphasis lands on terrible American histories. The current edition of mayfield brooks’s resonant, ever-evolving Whale Fall project, for example, transforms a former munitions warehouse on Governors Island into “an abysmal underwater world,” haunted by slave ships that doubled as whale ships, and buoyed by a poetically imagined affinity between the ancient leviathan and Black folk. —Apollinaire Scherr