Hittade det här i iTuneshjälpen:
" Creating a copy of a song in a new file format
You can save a copy of a compressed song file (for example, MP3) in an uncompressed song format (AIFF or WAV). For example, a song encoded in MP3 can be converted to WAV.
1 Choose Preferences from the iTunes menu, then click the Importing button at the top of the window.
2 Select the encoding format that you want to convert the song to, then click OK to save the settings.
3 Select a song in your library, then choose Convert Selection to MP3, Convert Selection to AIFF, or Convert Selection to WAV from the Advanced menu. (The menu item changes to show what´s selected in your Importing preferences.)
To convert all the songs in a folder or on a disk, hold down the Option key and choose "Convert Selection to" from the Advanced menu. All the songs in the folder or on the disk will be converted.
The converted song appears in its new format in your library."
Hoppas det kan hjälpa dig!