RatingMerge
RatingMerge is a tool that allows you to take the ratings from one iTunes library and bring them into another library, merging them with the ratings that are already there.
There are two situations where I've found this useful:
Work and Home: You have your music both at work and at home, and you want to take the ratings you've created at work and bring them home.
Multiple Users at Home: You and your wife/girlfriend/husband/dog each have your own computer and your own iTunes, but you share music. You each rate songs, but you have one iPod that you bring with you in the car. The iPod can only sync with one copy of iTunes. You want to use smart playlists like "Rock, 4 Stars" and you want all the music any of you has rated 4 stars.
RatingMerge is the tool. It'll combine the ratings from multiple copies of iTunes giving you a way to resolve conflicts.
Here's how it works.
First, you select the music library you want to import ratings from. The music library is a file that iTunes writes out every time you use it, and it contains a list of all the songs in the library and their ratings (among other things). It's located in
My Documents\
My Music\
iTunes\
iTunes Music Library.xml
So say you wanted to bring home the ratings you've created in iTunes at work and merge them with your iTunes at home. You'd need to bring home a copy of the iTunes Music Library.xml file from work.
When you launch RatingMerge, the first thing it will do is ask for this file:
Select it and hit Open. Next it will read in this file, and then scan your iTunes database looking for those songs.
Once it's done this, the main UI will appear, showing you a list of all the songs that it found in both locations.
If there are conflicts between the ratings in your local iTunes database and in the ratings you're importing, as you can see there are here, they will be noted in the list.
Select the songs whose rating you want to import, or click Select All, and then click Import Ratings Now. The ratings you've selected will be imported.
That's all this program will do - the only changes it will make to your iTunes database is to change the ratings of the songs you select in the list, to match the rating from the imported list. But "just in case", you should always back up your iTunes database before using a tool like this.
Download here:
If you have any trouble with it, please post a comment here and I'll try to address it. Thanks!