I find it fascinating how a lot of the collaborative tracks that I've heard come out great, even though there's little communication between the artists, just people throwing around a file. This should be done more often, so I'm throwing out this lsdsng I made in a few minutes just for this.
http://www.mediafire.com/download.php?cow63kmro38ncv9
You can make any changes you want, except:
-Adding more than six rows in the song screen
-Changing the BPM
-Editing Instruments
-Editing patterns (clone if you have to)
-Removing patterns
-Editing non-empty tables (A00 is left empty on purpose, don't use it)
-Please name new instruments.
Besides that, go crazy; have fun, steal other people's tricks. I'll call it done when it reaches about 4 minutes in length, or 5 different collaborators (Not collaborations! You can go back to it when someone's added more.)
After that I'll record it and upload it to chipmusic.org and soundcloud and credit every collaborator and release it under a CC-BY-NC-SA license and you can share it however you want and yadayada you know how it goes. If people like the idea we could do some more.