The answer a year later (for posterity)
First of all, yes, this in an old old post, BUT it is the #2 thread to pop up on Google when I typed in "how to clear property for contributing artist".
Therefore, for good of all the people in the world that have asked and been told to "Google it", here is the answer.
1.Highlight all the files that you wish to clear any sort of meta data from.
2.Right click and go to properties.
3.Click on the Details tab.
4.At the bottom of the Details tab, there is something that says "Remove Properties and Personal Information. Click on it. Don't worry it won't ruin anything.
5. A new panel will pop up, click on the second bubble option and BAM, you can select all the info that you want to clear for all those 93GB of music that were ruining your MP3 player artist lists or album lists or what ever.
You're welcome random internet person. Please enjoy the rest of the internet.
