Berlioz's Orchestration Treatise (1843) is a classic textbook by a master of the orchestra, which has not been available in English translation for over a century. This is a book by and about Berlioz, since it provides not only a new translation but also an extensive commentary on his text, dealing with the instruments of Berlioz's time and comparing his instruction with his practice. It is thus a study of the high craft of the most distinctive orchestrator of the nineteenth century.