The Electronic Triangle
by Dan Stowell
based on a dream by Philippa Law
Philippa dreamt of a magical orchestral instrument, an electric triangle which you drew in the air. The triangle would appear as three shimmering rectangles in the air, which you could play by striking just like the bars of an ordinary musical triangle.
Here is a relatively humble recreation of that instrument. Unfortunately you draw the triangles using a mouse on your computer screen, rather than actually drawing them in the air, and the triangles don't currently shimmer or twinkle quite as much as Philippa would like. But it's fun to play anyway. (And they do shimmer quite a bit - they just don't twinkle.)
It's written in Java - you can download the source code if you like: Triangle-1.1-source.tar.gz
mcld.co.uk > oddmu > triangle