A growing body of educational research has shown that children learn most effectively when they are engaged in designing and constructing things that are personally meaningful to them. Consequently, the challenge facing many researchers and practitioners has been to design a diverse collection of construction kits that support learning about many powerful intellectual and artistic ideas. In this thesis we report on the design and the implementation of a toolkit, called MICK, geared towards rethinking music education. MICK is a musical instrument construction kit that enables novices, particularly children, to design and build their own musical instruments. The electronics components and software tools in MICK make it possible to rapidly prototype a wide variety of instruments and other devices. The process of constructing a musical instrument with MICK also provides learners with many authentic opportunities for exploring and reflecting on important mathematical, scientific, and engineering ideas.