It's no co-incidence that the books by Piston, Rimsky-Korsakov and Berlioz ( ISBN-13: 978-0486269030) feature prominently on the shelves of anyone wanting better to understand how music works from an instrumental and orchestration perspective. Expensive (well over US$130 on Amazon at the time of writing) and heavy, though it is, it's well worth it and would last a lifetime. And Adler's superb grasp of the principles of how instruments work in an orchestral context (he is, after all, an accomplished composer) makes this book one to be recommended without hesitation. It is not length that should determine the quality of a book, of course. But now Adler's is by far the longest at over 1,000 pages including index etc – almost 15% longer than the third edition from 2002. These are all lengthy, substantial and thorough books. The new fourth edition of Samuel Adler's The Study of Orchestration amply retains its place in the top rank of the several excellent books on instrumentation and orchestration.