Music offers an intriguing context to engage children in electronics, programming and more. Over the last year we been developing a hardware and software toolkit for music called modular-muse. Here we describe the design and goals for these tools and how they have been used in different settings to introduce children to concepts of interaction design for music and sound design. Two exploratory studies which used modular-muse are described here with different approaches; a two day build your own instrument workshop where participants learned how to use both hardware and software concurrently to control synthesized sounds and trigger solenoids, and a middle school music classroom where the focus was only on programming for sound synthesis using the modular-muse Pd library. During the second study, a project called Pd Poems, a teaching progression emerged we call Build-Play-Share-Focus which is also described.