In 1999, Oliver Sacks, the eclectic neurologist who was dubbed the “poet laureate of medicine,” received a letter from a pianist, Anna H. “My (very unusual) problem, in one sentence, and in non-medical terms, is . . . I cannot read words, and music gives me the same problem.” Sacks was known for handwritten correspondence, but he called Anna—“this seemed to be the thing to do”—and invited her to his clinic.