We have two goals:
1 - to allow each composer as much freedom in composing their section as possible.
2 - to try to make this work flow from one section to the other.
In order to accomplish goal #2 there is a simple set of rules each composer must follow.
Your music will be cross faded with the track in front of it. This is not to be like a cross fade in itunes. This is supposed to sound like a continuation of the same piece. So your audio file must start on an exact measure of any meter with 4 on the bottom (quarter note.) 4/4 is fine, but so is 7/4 (NOT 7/8!) You will be coming from a /4 time that's holding one chord. You will start holding the same chord in /4 time and then progress to whatever you want WITHIN your two minute section.
What do I mean by "holding a chord?" I do NOT necessarily mean SUSTAINING a chord. It does not have to be strings or any other sustaining instrument all holding their note of a chord. It's better if it's not that. We want the listeners to have no idea where the transitions are (at best.) By "holding a chord" I mean that for the last part of your section, I could analyze it with traditional harmony as I (tonic, 1, home chord, etc.) The individual parts and notes can move, but no chord changes. And it would be better to avoid dissonances and leading tones (Fa, Ti.) "Hold" the chord as long as you feel is appropriate for a transition. Four to Eight measures if you're not sure - longer is safer. This is only for the beginning and end of your section. Within your section you can do ANYTHING (musical) you want.
Your music will be faded into the next section. So after you have had your fun with your section, have it come to your selected end key and tempo. "Hold" the chord for a while, allowing the next section to transition.
See the Section Chart to pick a section.