I have been asked to score a 3-minute \"industrial\" for a large (Fortune 500) company, and I would like to get a better idea of typical rates, retention of ownership issues, etc. Any guidance would be great.

The piece is to be used internally and played for their clients, but not broadcast. Unless I hear differently from you all, my intent is to charge a per-minute creative fee and license the music (i.e., retain ownership) for their intended uses. Thanks.