A tour of “Art of Native America: The Charles and Valerie Diker Collection,” on view at The Met Fifth Avenue through October 6, 2019. A visit to the Nevelson Chapel at St. Peter’s Church in Midtown Manhattan. And a trip to The Wallach Art Gallery at Columbia University for an insider’s view of the exhibition “Posing Modernity: The Black Model from Manet to Matisse to Today.”