I'm not an employee or customer, and I have no personal experience with this company
BUT
Tunecore
http://www.tunecore.com/ just came out with in the past few days, it seems to be a really great and easy way to get you or your clients music onto iTunes and many other online music distribution systems with a guarantee that the musician (or copyright owner) maintains all rights and liberties to the music and gets every penny made from the sale.
I invited a rep from Tunecore to drop in and field some questions about the program.
If this program is successful I know I have many clients who would love to get themselves onto iTunes and into such a mainstream distribution system.
so check it out!
Peter