App that automatically fills in year, genre, composer, etc. in iTunes

Is there a free app for Mac that can add all of this info to all the songs in my iTunes library?

check out iEatBrainz.. i just used it today for the first time and it mismatched some songs and didn't find some other in their databases, so just manually double check each song it names before u have it change the id3 tags

another alternative to iEatbrainz, especially if you know the album nyway is the apple script CDDB Safari Kit

http://dougscripts.com/itunes/scripts/ss.php?sp=cddbsafarikit

just put your tracks in a playlist, find the info in Gracenote and run the script