Currently Being ModeratedJun 15, 2012 8:37 AM (in response to vysis)
If for some reason you haev failed to maintain a backup copy, then redownload them following these directions:
Currently Being ModeratedOct 23, 2012 6:42 PM (in response to vysis)
there's a chance that iTunes deleted the song. Don't worry, you're not the only one with this problem. Other problems may include, but are not limited to missing album artwork, missing albums, incomplete albums, duplicates, and other exasperating shenanigans.