Richard Powers, A Cappella, Squier

An oil painter is the $250,000 winner of ArtPrize. A cappella gets its due: the Yale Whiffenpoofs celebrate their centennial and Sonos, the harmonizing indie group, performs live in the studio. And in the only radio interview he’s doing for his new book, “Generosity: An Enhancement,” the novelist Richard Powers finds his muse in genetic engineering.