Not sure what this is but it's quite fun.

http://seaquence.org/

Bizarre but fun.  Good find. 

http://seaquence.org/zj8w

My effort.

http://seaquence.org/d9gj6

Why am I getting

This page can't be displayed

from the two efforts posted 

Open it in Chrome. Not compatible with IE

That's great Snowy 

Works in Firefox, too.

http://seaquence.org/g6zn

I must say, Snowy's is superior to mine. And you're right, Freddy. Loads of fun there. I think I'll play a bit more.

My only problem with it is that there are only 2 octaves across 16 quarter-note measures to work with, which doesn't provide much latitude, musically. Still, it's fun to create some interesting (if a bit repetitive) arrangements.