In this introductory chapter, the framework of this book is established. First, an overview of the reception and first uses of the valved horn in Paris presents the problem to be addressed: why the valved horn took so long to be fully embraced by the Conservatoire. Then, the structure and topics of the book itself, as well as the central questions this book will address, are introduced for the period in question. This book demonstrates that technology does not simply march toward an inevitable “better.” It is people who are the driving forces behind whether a technology continues to be used. The Paris Conservatoire and its teachers laid the foundation for our current pedagogy, which makes the progression of these people and their individual works an appropriate focus to observe how change can take place in music, providing information which, in turn, can be applied to historically-informed performance of the applicable music literature of that period.