Originally Posted by kennyt
Not sure what you mean, the problem is I want to compress the entire collection to Apple Lossless or even MP3, but the HD I want to use to hold it won't fit the entire library in AIFF.
I'll bet you can do it this way:
1. Create another iTunes Library, by launching ITunes, while holding the option key down, and then choose the "Create new library" option.
2. From the Finder, navigate to where the source songs are. These are usually found in the location: ~username/Music/iTunes_Music/
3. Import sections of your first library into the second, by dropping folders (or groups of folders) from the finder window into the new iTunes window.
4. Once a section has been imported, select the music files within the "new" iTunes window, and from the iTunes "Advanced" menu, select "Convert selection to Apple Lossess". This will result in a copy of each file in Lossless format. The copy will have the same metadata needed to keep it categorized, etc.
5. To recoup space, delete the original source files from the newly created library.
6. Repeat steps 2-5 as needed to get the whole library over. The key is to do it in sections of small enough size, so your drive is not filled up.