Along with Paul Neave’s site, I’d forgotten about this little gem:
The sky is blue, they say. Well, these people do:
Click on Enter and take a gander at La Pâte à Son (you may find you have to load Shockwave and maybe other bits). It’s an intellectual challenge – once you have the main screen up and running (http://www.lecielestbleu.com/media/pateasonframe.htm), you can build your own pipework and add instruments to create some unusual sounds.
There are various controls embedded in the display – knobs can be rotated, levers pulled – it’s requires something of an exploration just to find out what everything does before you can get into the real business of creating.