You said: We will each pick from a selection of new released singles as to how each will do. Choices will be: No chart, Top 40, Top 20, Top 10 or Number uno.
After a three month period the winner gets to write your "music" column for an entire month.
the rules (which are concrete and can't be manipulated) are:

1. As ranked by industry journal Radio and Records.
2. The list of songs is picked from the new releases for the chosen format.
3. Picks must be made prior to 12 noon for the Monday week of adds to format.
4. Tracking will be by RRonline.com.

I say: sounds fine. But a couple of questions: Is "my" music column the main music story each week (example, this week's is Peter Searcy) or "Eye on the Scene?" I'm assuming you'll be willing to hit our deadlines and word counts. After all, what Metro Pulse does is so much less demanding than what you currently do.
And what happens if I win? I mean, I'm already writing and/or editing all of this anyway, so it doesn't seem like much of a prize.

If we start now, the 3 months will end the first week of November.