Many moons ago (probably years, I can't even remember) I found a Flash or Java applet (I don't know which!) online. It had a grid that you would place squares on, set a direction on each one (up, down, left, right) and when you hit play, it would generate music based on where you placed the blocks and the direction you gave them. The directions would determine how the blocks move across the grid, which would make the music change dynamically and seemingly never loop, if I recall. I was reminded of it by this, but it was different.

I can't find this thing again! Does anybody here know what I'm talking about?