“I have come to the conclusion that much can be learned about music by devoting oneself to the mushroom,” wrote the American avant-garde artist and composer John Cage. Maybe it’s the fact that without fungi all ecosystems would fail. Or it’s the experience of finding them hidden in nature. Or maybe it’s our knowledge of their psychedelic qualities. Or simply their charming shape. Mushrooms have been muses to artists from Beatrix Potter to Cy Twombly to Takashi Murakami. A new show—which includes, among many other works, Cage’s limited-edition Mushroom Book of recipes, observations, and illustrations—pays homage to fungi and their place in art and culture. —J.V.