Writing a proposal

Anyone have any advice on writing a proposal for a piece? I'm applying for this: The MSO Website - Cybec 21st Century Australian Composers Program and I have to write an outline of the piece I'd write if I were selected. How in-depth do I need to get for something like this? Should I outline a structure or plan for the entire piece? I mean I could end up writing anything by September/November. I could change my mind hundreds of times

It highly depends on the piece and on yourself.

In our half-year folio we had to submit one piece and sketches for the two next pieces. Thing is, I don't work with sketches - so I just wrote on a piece of paper "Sketch for the ensemble piece - I have absolutely no idea what I'm going to write for the ensemble piece."

I'm not recommending you do the same in your situation - but try and give them as much information as you have about what you're planning to do. You could say things about the instrumentation, pieces that have sparkled an interest and might serve as starting points, the use of material, its length, if it's going to have sections or movements, the title of the piece, just as much information as you have. And don't be afraid if you submit something that's a bit (or a lot) different than what you said you would. Just say that what you started off didn't work out, or that the second idea sounded like it would fit what they were asking for better.