[sdiy] Simple soldering kit, music/noise/midi related?

[MTG]

I was thinking of teaching basic soldering skills to the kids next door. 
Can anyone thing of a simple/cheap sound-making kit we could build? I 
remember as a kid doing a little organ from radio shack. What would be 
even better would be something that had MIDI in or out so they could 
hook it up to their Yamaha home piano and really annoy the parents.

GB