Last Saturday afternoon, at Dia: Beacon, the art critic Christoph Cox, casual in a grey shirt and jeans, was leading a group through a gallery of hulking metal sculptures by John Chamberlain. It was a dramatic scene, but these people had assembled to hear Mr. Cox discuss something far subtler. “It’s the most overlooked work in the entire museum,” he told them. “It’s invisible, so it’s very easy to miss.” Read More