Donald Trump is about to order the building of a wall along the US-Mexican border. As people who live in the borderlands already know, walls already exist on the border. They are mere artifacts among many others in the land where two cultures meet in conflict and reconciliation. The photographer Richard Misrach has been photographing the borderlands since 2004. Like a sort of desert flâneur, he's also been gathering artifacts of the contact zone, from discarded backpacks to shotgun shells, and turning them over to the composer Guillermo Galindo, who converted them into instruments. The story of this collaboration is told in Border Cantos, as well as an exhibition at the Crystal Bridges of American Art through April 27, 2017.