I have seen many people who ask about changing the names of their files and how they can not change the artist name or song title, but only the file name. If you have musicmatch (even the trial version) open the files whose artists you want to change. Then highlight them and right click - then edit track tags. You may change the title and artist without effecting the fileneme.
I am just putting this hear rather than responding to all of the question threads. Sorry if this has been said before.