This half day course introduces the field of musical interface design and implementation. Participants will learn and practice key aspects of the theory and practice of designing original interactive music technology with case studies including augmented and sensor based instruments, audio-visual instruments, mobile, and networked music making. Digital technologies offer powerful opportunities for the creation and manipulation of sound, however the flexibility of these technologies implies a confusing array of choices for musical composers and performers. Some artists have faced this challenge by using computers directly to create new musical forms. However, most would agree the computer is not a musical instrument, in the same sense as traditional instruments, and it is natural to ask ’how to play the computer’ in a way appropriate to human brains and bodies. To attempt to answer this question in the course, we draw from the International Conference on New Interfaces for Musical Expression (NIME) [1, 2], which began as a workshop of CHI 2001 [3] and explore connections with the established field of human-computer interaction.