How can I change the metadata of my songs all at once? I have a bunch of songs for which I'd like to change the metadata (really just want to change capitalization for all of them). I'm not changing a field in all songs to one value, so selecting them all in iTunes won't work. They are AAC files. Is there an easy way to do this? Not having to download a third-party app would be nice, but I doubt it'll be that easy (maybe someone can prove me wrong :)).
You could also run a script like this in AppleScript Editor:

tell application "iTunes"
    repeat with t in selection
        tell t
            set name to my titlecase(name)
            set artist to my titlecase(artist)
            set album to my titlecase(album)
        end tell
    end repeat
end tell

on titlecase(x)
    do shell script "ruby -rubygems -KUe 'require \"titlecase\"
    print ARGV[0].titlecase' -- " &amp; quoted form of x
end titlecase


The titlecase gem can be installed with sudo gem install titlecase.