You can tell a lot about a book from its bibliography. It’s the non-fiction equivalent of skipping to the final page of a novel. Turn to the end of Ian Bostridge’s Schubert’s Winter Journey — a study of the composer’s celebrated song cycle Winterreise — and you’ll find monographs on ornithology, weeping as a cultural phenomenon and wood sculpture in Renaissance Germany, essays on Samuel Beckett and the history of the mail coach, and the rather forbidding ‘Regulation of floral organ abscission in Arabidopsis thaliana’.