John (John Russell Brown is Professor of Theatre at the University of Michigan, Ann Arbor and has taught in the past at a variety of colleges including New York University and Stanford University.) Brown 
What is Theatre? [PDF ebook] 
An Introduction and Exploration

This major introductory textbook is from one of the leading educators working in theatre today. What Is Theatre? will make its reader a better playgoer, responding more fully to performance, with a keener appreciation of all the resources of theatre-acting, design, direction, organization, theatre buildings, and audiences. By focusing on the best professional practice and the most helpful learning processes, Dr. Brown shows how to read a play-text and to see and hear its potential for performance. Throughout this book, suggestions are given for student essays and class discussions, to help both instructor and reader to clarify their thoughts on all aspects of theatre-going.
While the main focus is on present-day theatre in North America, history is used to illuminate current practice. Theatres in Europe and Asia also feature in the discussion. A view is given of all contributors to performance, with special emphasis placed on actors and the plays they perform. This textbook is not tied to a few specific play-texts, but designed to be effective regardless of which play a student sees or reads. In Part Two, leading practitioners of different generations and cultural backgrounds describe their own work, providing a variety of perspectives on the contemporary theatre. All this is supplemented by nearly 100 black and white and color illustrations from productions, working drawings, and plans. This new text engages its readers in the realities of the theatre; it is up-to-date, comprehensive, and packed with practical advice for understanding how theatre works and how plays come alive in performance.
John Russell Brown is professor of Theatre at the University of Michigan, Ann Arbor, and has taught at a variety of colleges including New York and Stanford Universities. For 15 years he was an associate director of the National Theatre in London, and he has directed plays in many other theatres including Cincinnati Playhouse, the Empty Space in Seattle, and the Clurman Theatre in New York. Professor Brown has written extensively about theatre, especially about Shakespeare and contemporary theatre. He is editor of The Oxford Illustrated History of Theatre.