The Banana Piano
The technology bihind the Banana Piano was a 'casual invention'. It is called the Makey Makey, so that you can tell the kids to "go on, makey makey something"!
Makey Makey is a small circuit board, that connects on one side to a computer and on the other side to ... well, virtually anything. Anything that can conduct just a little bit of electricity. Each such connected object can work as a computer keyboard key. It is then up to us to make the key do something on the computer. It can play a music note, it can make Jerry jump. Whatever is possble to do with keyboard keys.
That's how we make the banana piano. On the cunputer we run a program that plays piano notes on press of keyboard keys. We then connect each banana to different ports of Makey Makey to emulate the respective keys of the keyboard. Simple!
Here's a video of one of our Tinkerer playing a set of drums through Makey Makey, which we created in a similar way as the Banana Piano.
The next activity is Squishy Circuits. A 3 year old can actually play with electric circuits!