Musical instruments that "play themselves" have a long and storied history that reaches back thousands of years. While the twentieth century saw the phonograph and its descendants relegate these creations of the mechanical golden age to a veritable basement, the twenty-first century has seen them revitalized. A new breed of musical machines has emerged that synthesizes physical and computational worlds. These artificial agents may seem cold and alien, but they can also be understood as expressions of fundamental human values and goals. Their abilities and characteristics are unique from those possessed by humans and offer novel creative possibilities to artists and musicians who use them.The purpose of Musical Machines: History, Theory, and Techniques for Makers and Musicians is to inspire the creativity of musicians, engineers, and makers by helping them imagine, design, build, and play with such machines. This requires exploring our complex relationship with artificial agents and confronting questions of motivation and meaning arising from their increasing abilities. It involves developing historical knowledge, technical skills, and artistic sensibilities. Author Scott Barton addresses these needs by detailing philosophical questions, key concepts, and a historical landscape that provides an artistic and technical context to help explain what these machines are and how they have been used. Technical lessons devoted to mechanisms, actuation, electrical circuits, programming, and communication are provided on the companion website, equipping aspiring builders with requisite skills through project-based activities. A template for the design and realization process provides a basis for examples in the major instrument categories--strings, percussion, and aerophones. First-person perspectives from prominent builders in the field illuminate how design approaches can vary, encouraging the development of individual voices. Conscious that the point of these efforts is to make music, in the final chapter Barton describes concepts and techniques involved when composing with and for musical machines.