Raspberry Pi Orchestra

The Raspberry Pi is cheap enough that it could be used instead of instruments in a school orchestra. Each one needs a small speaker, but not necessarily a screen - either a mouse or keyboard can control sound synthesis. If some devices had screens, they could be used to "conduct" (via a shared network clock signal, with tempo variations as appropriate), or even distribute code for remote execution elsewhere. A technical approach to synthesising good quality sound can build on the source code for the recently released Sonic Pi, and networking ideas can be borrowed from international laptop orchestras:

https://esp-mcmaster.wikispaces.com/Laptop+Orchestra+bibliography