Unless otherwise stated, the copyright notice for all of my work is:
©[year] Noel Lairson
Non-commercial/Creative Commons work: OK, provided you tell me about it and send me a link to the finished product (noel noellairson com)
File sharing: Also OK, provided the copyright notice remains. It would also be cool if you'd drop a buck or 2 into my PayPal account (nlairson earthlink net)
Commercial work (Comps, samples, etc): Sure, but I want a cut. Get in touch with me at the noellairsondotcom email and we'll come to some kind of agreement.
Advertising: Never. Don't even ask.
I think that's pretty clear, but I'll spell it out further: I don't want to stand in the way of anyone doing any cool derivative work, I want to be paid if there's derivative work that is sold commercially; file-sharing is a reality to contend with, so complaining about it is silly - but there IS a tip jar, if you would be so kind; and I hate nothing more than hearing a piece of music I have loved for years being used to sell me insurance - I'd be happy to take a commission, but nothing I release as my art shall have any kind of second live as a jingle.
Why copyright? As much as I support the ideas behind the various Creative Commons-type movements, copyright is written in the Constitution and has extensive legal history behind it, and I care enough about the no advertising thing that I assert full copyright over my work.