The Hyperscore graphical computer-assisted composition system for users with limited or no musical training takes freehand drawing as input, letting users literally sketch their pieces. Designing an intelligent, intuitive system that enables novices-particularly children-to compose music is a difficult task. We can view the problem as a spectrum of tasks that range from the development of musical algorithms for automating the compositional process to designing an appropriate interface for humans to interact with the machine. The Hyperscore software tool attempts to address both of these issues.