Book excerpt: This new edition of leading opera critic Rupert Christiansen's perennially popular Pocket Guide has between extensively revised, and incorporates many more operas from all periods, including recent works by Philip Glass, Mark Anthony Turnage, Thomas Adès and George Benjamin. Whether you are a first-timer at La Boheme or a seasoned Wagnerian, every opera-goer can benefit from a little background information, and this book aims to provide just that. Accessible and easy-to-use, it contains entries for over a hundred works, both familiar and unfamiliar.