Wolfgang Amadeus Mozart has died a hundred deaths, more or less. Here's a new one: darkness. Doctors over the years have resurrected the story of Mozart's death again and again, each time proposing some alternative horrifying medical reason why the 18th century's most celebrated and prolific composer keeled over at age 35. A new monograph suggests that Mozart died from too little sunlight. The researchers give us a simple theory. When exposed to sunlight, people's skin naturally produces vitamin D. Mozart, toward the end of his life, was nearly as nocturnal as a vampire, so his skin probably produced very...