Moog Product Design Engineer Amos Gaynes shares his perspective on electronic musical instrument design, with a focus on the human-machine interface as a conduit for creative expression. This comprehensive conversation explores the art and science that informs the design process -- from understanding the needs of the performer to working with various technologies which can meet these needs. We'll tour the historical innovations in expressive musical technology, examine the state of the art, and maybe even peer into the speculative future.