can't edit tags for album purchased from itunes store

I purchased an album from the iTunes store and I can't edit any of the tags for it, all of the fields are greyed out. (This is the case for every song in the album). Here's a screenshot:

I tag my songs pretty specifically and use them to keep things organized and for playlists and such. I've also bought albums from the iTunes store before and never had this issue. Anyway I can edit the tags?